Seven people died, including four Ugandan soldiers, in clashes on Lake Edward between forces from the Democratic Republic of Congo and Uganda, according to a Congolese official quoted by the AFP news agency.

Lake Edward straddles the border between the two countries.

The administrator of Congo's Beni region, Donat Kibwana, is quoted by AFP as saying that a Congolese naval patrol was attacked on Thursday morning "by a Ugandan patrol boat".

The Ugandan boat sank and four Ugandan soldiers and three civilians died, he added.

Jaribu Muliwavyo, a local MP, told a Congolese Virunga Business Radio that the clash was over fishing rights.

A Ugandan army spokesman, Brig Richard Karemire, blamed the attack on "some gunmen who hurled a grenade onto our patrol boat", reports Uganda's New Vision newspaper.

He is quoted as saying that two Ugandan soldiers had been critically injured.