~ The kidnappers have offered to negotiate the release of the hostages.

ABUJA, Nigeria -- Eight foreign workers, including one American, were kidnapped from a drilling rig off Nigeria's oil-rich southern delta Friday in the latest incident highlighting the tenuous security of oil operations in Africa's largest crude producer.

The kidnappers have offered to negotiate the release of the hostages -- six Britons, the American and a Canadian -- taken before dawn from the drilling rig Bulford Dolphin, according to the company that operates the rig.

Oil prices jumped by more than $2 a barrel Friday after the report revived concerns about the stability of Nigerian supplies.

Analysts said anxiety over Iran's nuclear ambitions also supported crude futures.

Sheena Wallace, a spokesman for Aberdeen, Scotland-based Dolphin Drilling Ltd., said that they understand that the group of kidnappers "has been in touch with the local companies about negotiations."

She said she did not have the names of the missing crewmen, information about demands or what group was behind the kidnapping.

No demands made

Police spokesman Haz Iwendi said in the capital, Abuja, that no group had claimed responsibility and no demands had been made.

"Security agencies are trailing them to secure the release of the hostages as soon as possible," Iwendi said.

Presidential spokeswoman Remi Oyo said "the abduction was the result of a misunderstanding between communities and the oil company involved." She did not elaborate.

Militants in the Niger Delta region have blown up pipelines and kidnapped foreign workers in recent months to press their demands for a greater share of the country's oil wealth.

Other groups have kidnapped oil workers as bargaining chips to prod companies to increase jobs or improve benefits. The kidnappings usually end peacefully.

President Olusegun Obasanjo promised more funds to help the navy secure oil assets in the Gulf of Guinea.

"You have to ensure that our economic life-wire, which is maritime, is secured," Obasanjo said at a parade celebrating the navy's 50th anniversary. Oil exports, mostly from the delta region, account for more than 95 percent of Nigeria's foreign earnings and more than 80 percent of total government revenue.

Wallace said by telephone from Aberdeen that the kidnappers struck the platform, which had 84 people on board, about 5 a.m. Friday. The rig was about 40 miles off the Nigerian coast.

Drilling suspended

She said drilling had temporarily been suspended and that the families of the kidnap victims, as well as other crew members, had been contacted.

Last month, an unidentified gunman riding a motorcycle shot and killed an American riding in a car to work at the offices of the U.S. drilling equipment maker Baker Hughes Inc. in the southern Nigerian oil hub of Port Harcourt.

Nigeria, which normally pumps 2.5 million barrels of crude a day, is the fifth-largest source of oil imports to the United States. Unrest in the country has cut production and helped drive oil prices higher on international markets.