September 20, 2007

Encouraging Diamond Grades From Underground Test Mining at Kono

Mano River Resources Inc. (“Mano” or “the Company”) the TSX-V and AIM-listed exploration and development company focussed on West Africa, provides a progress update on the Kono kimberlite dyke diamond project in Sierra Leone. The Kono project is a Joint Venture between Stellar Diamonds Ltd (“Stellar”) (49%) and Petra Diamonds Limited (“Petra”) (51%). Mano River is a 68.5% shareholder in Stellar, which recently completed a £4.2m pre-IPO financing and plans to list on AIM.

The salient points from the Petra news release of today are as follows:

  • The development programme has made further solid progress, with test mining of a number of shafts delivering encouraging results
  • Test mining has commenced on three shafts where in-situ diamond grades of between 50 and 80 carats per hundred tonnes (“cpht”) have been achieved
  • Petra believes that the test shafts have a high likelihood of developing into economic production operations
  • 2,809 diamonds totaling 241.7 carats recovered from trial mining to date (February 2007: 638 diamonds, 58.8 carats)
  • Petra attribute the increase in diamond recoveries in recent months to better quality kimberlite now encountered, more consistent kimberlite fissures and better fissure widths;

Adonis Pouroulis, Chairman of Petra, commented; “We are pleased to report the further positive progress at the Kono project. The trial mining is going well and whilst further work is required in order to infer a representative grade and value, the results to date support our expectations for the Kono project and we progress with confidence into the next phase of the development. The quality, consistency and width of the kimberlite now encountered are all positive signs for the future development of economic operations”

Stellar’s CEO, Karl Smithson comments: “We are very encouraged by the news given by Petra Diamonds from the Kono operations. We would like to commend Petra, our partners, on their diligent and effective management of the project. Petra is the world leader in underground kimberlite dyke mining and they have assembled a first class operational team that we are confident can bring success to the project.”

Petra also provided the following further details:

Test Shaft Development

The development programme at Kono has achieved some encouraging results in recent months with potentially economic kimberlite fissures having been opened. Diamond yields, fissure widths and the underground mining and geological conditions have enabled Petra to concentrate their test shaft efforts on three very promising diamondiferous kimberlitic fissure targets.

To date five shafts have been sunk, each to a depth of 30 metres. Three of these shafts are now at the test mining stage on the 30 metre level and have been returning satisfactory in-situ grades of between 50 and 80 cpht. These shafts display a consistent, near vertical dipping fissure line with very encouraging in-situ shaft sinking grades; fissure widths vary between 40 centimetres (“cm”) and 200 cm with satisfactory mining conditions having been experienced to date. Two shafts were discontinued because diamond recoveries during the shaft sinking and test mining phases did not match the potential of the other three shafts.

The test shafts are at advanced levels of development and the processing of a limited amount of weathered, diluted and mixed diamondiferous kimberlitic material extracted during shaft sinking yielded 2,809 diamonds totalling 241.7 carats. The ten largest diamonds ranged in size from 0.65 carats to 7.2 carats. Although the diamond yields are encouraging from a small amount of material processed, Petra is of the opinion that the scale of the test work conducted to date is too limited to arrive at any representative grade or value and will report on further findings when available.

The next phase of the project will excavate approximately 100 metres of kimberlite along strike of the mineralised body at each shaft, so as to process approximately 1,000 tonnes of clean kimberlite to obtain acceptable run of mine grades and diamond values to be used in proposed business plans. It is anticipated that this programme will be complete by March 2008.

Exploration Development

During shaft sinking operations Petra found that, due to the highly saprolitised nature of the rocks in this locality, the silicate and spinel kimberlite indicator minerals have been destroyed, in many cases to depths of up to 20 metres. It has further been ascertained that ilmenite-deficient kimberlites exist in the area. These conditions may mean that kimberlite pipes were overlooked during mining and exploration operations carried out by previous operators in the area and Petra is considering the flying of a low-level helicopter borne electro-magnetic survey over the licence areas so as to prospect for these potential deposits.

Petra Notes: It should be noted that the potential quantity in this report is conceptual in nature, there has been insufficient exploration to define a Mineral Resource and it is uncertain if further exploration will result in the determination of a Mineral Resource.

For further information on Mano River Resources and Stellar Diamonds Limited, you are invited to visit the Company’s website at or contact:

Mano River Resources Inc
+44 (0) 1235 810 740
Tom Elder / Luis da Silva

Stellar Diamonds Limited
+27 82 802 8802
Karl Smithson, CEO

Pelham PR
+44 (0) 20 7743 6670
Charles Vivian

Panmure Gordon (UK) Limited
+44 (0) 20 7614 8384
Edward Farmer

GMP Securities Europe LLP,
an Appointed Representative of Panmure Gordon (UK) Limited
+44 (0) 20 7459 3606
James Hannon

Notes to Editors:

About Stellar Diamonds Limited

Stellar Diamonds is a 68.5% owned subsidiary of AIM and TSX-V listed Mano River Resources Inc. Stellar plans to list on London’s AIM market as an integrated diamond miner and explorer with a focus on West and Central Africa. The Company’s current portfolio of diamond properties and joint ventures in West Africa is summarised as follows:

    A 49% interest in a Joint Venture with Petra Diamonds on the Kono Kimberlite Dykes project in the Kono diamond fields of Sierra Leone, where test mining has commenced and commercial diamond production is scheduled for 2008.

    A 50% interest in a JV with Trans Hex Group in the Weasua cluster of diamondiferous kimberlite pipes in Liberia, where bulk sampling to determine diamond grades and value is currently underway.

    A 100% interest in the Mandala alluvial and Bouro kimberlite dyke project in Guinea, where a non-43-101 indicated alluvial diamond resource of 550,000 carats has been established and where high grade kimberlite dykes are present.

    A 15,000km2 reconnaissance licence in western Liberia where diamond bearing kimberlites and numerous high interest mineral indicator anomalies have been discovered.

    A JV with BHP Billiton, who are earning into an initial 51% interest in the south-eastern Sierra Leone tenements. The joint venture has located extensions of the high-grade diamondiferous Tongo dyke field and identified numerous geophysical targets that are currently being drill tested.

    Two licences in south east Sierra Leone where kimberlite has been discovered and indicator mineral anomalies require further follow up work.

    A JV with African Aura in Liberia where exploration is ongoing to earn into a 78% interest in the diamond rights of the 400km2 north Bea exploration project.

    A 100% held interest in the diamond rights of the 1,000km2 Bea MDA licence in Liberia where indicator mineral anomalies have been generated and require further follow up work.

    An agreement with De Beers to access their regional Guinea database, where an independent consultant has reviewed the data and target selection is now ongoing.

Mano’s Qualified Person responsible for reviewing the content of this release is its President & CEO, Dr Tom Elder, who holds a BSc and Doctorate in Geology from Durham University in the UK, is a Fellow and former Member of Council of The Institution of Mining and Metallurgy and a Fellow of The Geological Society.

The TSX Venture Exchange has not reviewed and does not take responsibility for the adequacy or accuracy of this release