Militants who abducted 10 crew members from a tugboat off the coast of Cameroon in West Africa are threatening to kill their hostages if their demands are not met within three days.

The militants boarded the tug, owned by French maritime services company Bourbon, just after midnight on Friday carrying small arms.

Three speedboats arrived at the tug while it was at an offshore oil terminal in the Gulf of Guinea, said Bourbon company spokeswoman Stephanie Elbaz. The tug, Bourbon Sagitta, was operating in support of an oil tanker that was being loaded with crude when the attack occurred.

Two militia groups — Niger Delta Defence and Security Council and the Bakassi Freedom Fighters — have claimed responsibility for jointly carrying out the abductions. Both groups have operated since 2002 in the Bakassi region, on the Cameroonian border with Nigeria.

"I personally led the attack," Ebi Dari, a Niger Delta Defence and Security Council commander, told Reuters.

Dari said if the Cameroon government doesn't respond to their demands within three days, the hostages will be killed.

The details of their demands have not been provided but Dari said they are connected to autonomy talks for the border region.

"We want to talk to the Cameroon government," Dari said. "If they think this is child's play, we are going to kill them in three days, one by one."

Dari said his insurgent group also doesn't want oil firms operating in the oil-rich Bakassi peninsula.

Cameroon took full control of the petroleum-rich land in the Bakassi region in August after an arduous border dispute with Nigeria.

Many Nigerian residents opposed the handover, and since then there have been low-level attacks from militants who claim the region should have more autonomy or even full independence from Cameroon.

Gunmen preying on oil plants

Six of the hostages are French, two are from Cameroon, one is Tunisian and one is Senegalese.

Five other crew members are aboard the tug, Elbaz said. They are safe and it is believed that none of the hostages was injured in the attack, she said.

The company is working with the French Foreign Ministry to ensure the quick release of the hostages, she said.

Elbaz declined to provide further details, citing the need for discretion.

Gunmen preying on oil plants, oil boats and fishing boats have become common in the area over the last year.

Most of the Gulf of Guinea's coastline is uncontrolled and vulnerable to attack. The area has become one of the world's most-pirated waters.

Similar attacks in other Gulf of Guinea countries are also common, including in Nigeria, Equatorial Guinea and Benin.

With files from the Associated Press and Reuters