DAR ES SALAAM (Reuters) - The police in Tanzania arrested three Chinese nationals and seized hundreds of elephant tusks in the past week in anti-poaching raids in the commercial capital Dar es Salaam and the southern town of Mtwara.

A total of 797 tusks were seized in three raids, officials said on Tuesday, representing the slaughter of about 400 elephants.

"706 tusks were confiscated in Dar es Salaam on Saturday alone," said Mr Chikambi Rumisha, a spokesman for the Natural Resources and Tourism Ministry. The tusks were found in sacks of garlic at the house of the Chinese nationals.

"Police seized 89 elephant tusks in Mtwara last week, while two elephant tusks were found by authorities in Dar es Salaam yesterday," Mr Rumisha said.

Well-armed criminals kill elephants and rhinos for their tusks, largely due to increasing demand in China for ivory ornaments and folk medicines. The police say most of the tusks smuggled from the east African country end up in Asia.

International trade in ivory was banned in 1989 after the population of elephants dropped from the millions in the mid-20th century to about 600,000 by the end of the 1980s.

Last year, a Tanzanian member of Parliament said poaching was out of control with an average of 30 elephants being killed for their ivory every day.

In August 2011, the Tanzanian authorities seized more than 1,000 elephant tusks hidden in sacks of dried fish at Zanzibar port and destined for Malaysia.