Militants in Nigeria's oil-rich southern delta on Monday released their last remaining foreign hostages — two Americans and one Briton — more than five weeks after the oil-industry workers were kidnapped, officials said.

Abel Oshevire, spokesman for the Delta state government, said Americans Cody Oswalt and Russell Spell and Briton John Hudspith were released just before dawn and were now with the local governor, James Ibori.

"They are here with us now and are all in good health," Oshevire told reporters.

Militants of the Movement for the Emancipation of Niger Delta took nine foreign oil workers hostage Feb. 18 from a barge owned by Houston-based oil services company Willbros Group Inc., which was laying pipeline in the delta for Royal Dutch Shell. The group released six of the captives after 12 days in captivity.

Militants have launched attacks against the oil industry in the world's eighth-largest pumper of crude in an effort to get a bigger cut of the oil revenues held by the federal government. The southern Niger Delta region remains deeply poor despite the oil pumped from beneath them.

Attacks on installations in the region have cut oil production by 20 percent, sending prices higher on international markets.

In exchange for the release of the hostages, the militants had demanded the government free jailed ethnic Ijaw leaders and Royal Dutch Shell pay $1.5 billion in compensation to Ijaw communities for oil pollution.

Ibori said no ransom was paid, but added now that the hostages had been released, "the pertinent issues raised by the youths on the Niger Delta condition will have to be addressed."

Foreign oil workers are frequently taken hostage in Nigeria, and most are released unharmed.