Nigerian security officials say gunmen have killed one foreign worker and kidnapped another at a compound for foreign oil workers in the Niger Delta region.

The officials say the gunmen attacked a facility housing workers of the Italian oil company Saipem Thursday. The worker killed and the one kidnapped are believe to be Colombian nationals.

There was no immediate claim of responsibility for the attack.

Earlier this week, the Nigerian militant group Movement for the Emancipation of the Niger Delta (MEND) issued a statement saying it was ending a four-month voluntary cease-fire.

The group threatened to resume a campaign of violence against oil production facilities and foreign workers in the southern Nigerian region.

Following the May inauguration of Nigerian President Umaru Yar'Adua, MEND announced a voluntary truce to allow for peace talks with the incoming government.

Militant groups in the region are seeking a greater share of the region's oil wealth for local communities. Most Niger Delta residents are impoverished despite the billions of dollars the government and oil companies reap from oil production.

Nigerian government officials and militants recently held several meetings in the Niger Delta aimed at ending violence. Unrest in the region has reduced Nigeria's total oil output by 25 percent since early last year.

Many armed gangs have taken advantage of the unrest to kidnap foreign workers for ransom.

Some information for this report was provided by AFP, AP and Reuters.