Police in Tanzania say they have seized 110kg of suspected uranium and arrested five people, including a national of the Democratic Republic of Congo.

In its raw form - yellow powder - uranium can be used to make radioactive material for the nuclear industries.

This is a dangerous issue

Director of criminal investigations, Adadi Rajab

The suspected uranium, which was ready to be sold in four plastic containers, came from a neighbouring country, but investigators will name it only when an investigation has been completed.

The containers were transported through three towns in south-western Tanzania, including Kigoma.

'Just business'

One of the five people arrested, a Congolese national, has been named as Makambo Mayunga.

The other four are all Tanzanians, including a woman who is an economist with the civil service.

Director of criminal investigations Adadi Rajab told the BBC that it was not yet clear if the find was linked to terrorism but thought "they were just doing business".

He said that in recent months, five tanks of suspected uranium had been seized.

Embassy bombings

Mr Rajab warned Tanzanians to beware of handling the hazardous material without taking proper safety precautions.

"This is a dangerous issue," he said.

Fourteen tonnes of raw uranium are necessary to produce a single nuclear weapon, according to the International Atomic Energy Agency, based in Vienna.

"Natural uranium is a long, long way from being enriched," IAEA spokesman Mark Gwozdecky told BBC Newsonline.

He said that if the substance seized in Tanzania was indeed uranium, it would have had to go through facilities monitored by the IAEA to be enriched.

Three countries in Africa are officially listed by the World Nuclear Association as uranium producing countries.

They are Niger, Namibia and South Africa.

But other sources say Algeria, DR Congo, Gabon, Malawi, Zambia and Zimbabwe also produce uranium.

The BBC's Premy Kibanga in Dar es Salaam says that already in 1998, uranium was seized in Tanzania and three people arrested.

That same year, the US embassies in Dar es Salaam and Nairobi were destroyed in bomb attacks which killed more than 200 Kenyans and 12 Tanzanians, and injured an estimated 5,000 others.