LOME (REUTERS) - Authorities in Togo have seized nearly four tonnes of ivory - the tusks from over 500 dead elephants - hidden in containers destined for Vietnam, officials said on Monday.

The tusks, disguised as cashew nuts and timber, were found late last month, underscoring a flow of ivory to Asia that environmentalists warn is decimating elephant populations and diplomats say also risks fuelling conflict in Africa.

Mr Kotchikya Okoumassou, a senior official in Togo's environment ministry, said the tusks were found in two seizures in the port of Lome, one on Jan 22 and another on Jan 28.

Some 500 elephants would have been killed in the haul, which has a value of around US$8 million (S$10.2 million) on the international market, he added.

Two locals and a man from Vietnam, where the containers were headed to, were arrested but it was not clear where the ivory came from.

"Togo only has 115 elephants so it is clear that the ivory did not come from here," Mr Okoumassou said.

The international trade in ivory has been banned but conservationists say African elephants are being poached at an alarming rate, especially in Central Africa.

The United Nations warned last year that the ivory trade had become an important source of funding for armed groups and was a growing security concern, especially in Cameroon, the Central African Republic, Chad and Gabon.

Elephants are hunted for their tusks, which are mainly used for carvings but are also used in traditional medicines.

The demand mainly comes from Asia, home to growing economies that are increasingly expanding into Africa.