"Tribal negotiations are being conducted with the kidnappers, with the participation of local security officers," the source, requesting anonymity, told AFP.

He said that local authorities opted for negotiations, rather than force, in seeking the release of the three tourists who were seized by tribesmen on Friday in southern Yemen.

The kidnappers, who belong to the Al Fadl tribe, have demanded the release of a relative who is a public sector employee and had been in custody in Sanaa for a "work-related fault," a security official said on Friday.

The tourists were part of a convoy travelling from the eastern region of Hadramut to the southern port city of Aden. They were attacked by tribesmen in Abyan province, he said.

The vehicle carrying the three tourists lagged behind the convoy, allowing the tribesmen to seize the car in Shaqra district, some 150 kilometres (95 miles) east of Aden.

A local authority official on Saturday said the hostages were still being held by the kidnappers in the same area of Shaqra.

AFP

Tribes have abducted more than 200 foreigners over the past 15 years in attempts to extract concessions from the central government, whose writ extends with difficulty over the lawless countryside.

Although kidnappers' demands are normally met, allowing hostages to be freed unharmed, three Britons and an Australian seized by Islamists in December 1998 were killed when security forces stormed their hideout. `