A Malawi and Tanzania delegation has arrived in Mozambique to meet that country’s former President Joachim Chisano to mediate on the dispute over Lake Malawi between the two countries.

Malawi and Tanzania will ask Mozambique’s former president Joachim Chissano to mediate a border dispute over Lake Malawi amid oil exploration, Foreign Minister Ephraim Chiume told a news conference on Tuesday.

“Having failed to reach a consensus, we are leaving the matter in the hands of the former heads of state of SADC [Southern African Development Community] countries to help mediate,” Chiume said.

Principal Secretary in the ministry of Foreign Affairs Patrick Kabambe confirmed delegates from the two countries have taken their concerns to Chisano.

The two countries are at odds over their frontier on the southern African lake where each of the poor nations hopes to discover valuable natural resources.

Based on an 1890 colonial agreement, Malawi claims ownership of the whole of Lake Malawi.

Tanzania insists that half the lake falls within its borders and is already eyeing it for natural gas exploration.

The contentious part is a largely undeveloped swathe of the lake, where Malawi has awarded a licence to British firm Surestream to explore for oil in the northeastern waters near Tanzania.

The 29 600km² body of water is Africa’s third-largest freshwater lake and lies in the Great Lakes system stretching along the East African Rift.

It is a major tourism attraction in Malawi and straddles one third of the country’s territory.

Tanzania calls it Lake Nyasa, taken from Malawi’s colonial name.