A Nigerian militant group says it has foiled an attempt to rescue four foreign oil workers that the group took hostage early last month.

In an e-mail to reporters Wednesday, the rebel Movement for the Emancipation of the Niger Delta (MEND) says the Italian oil company, Agip, tried to bribe guards watching the hostages. It says Agip offered the guards about $540,000 for the release of the three Italians and one Lebanese worker.

There was no confirmation of the report from Agip.

Armed men kidnapped the workers during an attack on an oil installation in the oil-rich Niger Delta region December 7.

The militant group has said it will not accept a ransom for the workers and that rescue attempts will endanger their lives. The group instead wants Nigerian authorities to release two jailed militant leaders.

The militants' stated goal is for villagers in the Delta to get a greater share of the region's oil wealth.

Attacks and kidnappings in the Niger Delta have cut Nigeria's oil production by up to 25 percent over the past year. The country normally pumps some 2.5 million barrels of oil a day.

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