PORT HARCOURT (Nigeria), Oct 2: Nigerian militants in speed boats attacked a Royal Dutch Shell oil pumping station on Monday, killing soldiers and ending a period of relative quiet in the volatile Niger Delta.

An oil industry source said the militants killed five of the 15 soldiers guarding the Cawthorne Channel facility, located in Rivers State in the eastern delta. An army spokesman confirmed soldiers were killed but he did not know the exact number.

No details were immediately available on whether the attack had any impact on production. Shell already has 495,000 barrels of oil equivalent per day shut down at fields it operates in Africa’s top oil producer, mostly because of militant attacks.

“About 17 militants attacked our soldiers. The militants came in several boats. They succeeded in sinking two of our boats with soldiers inside,” said army spokesman Sagir Musa, adding that several injured soldiers had been brought to Port Harcourt.

A self-styled Joint Revolutionary Council, which says it represents three militant groups, claimed responsibility for the attack and demanded the release of Mujahid Dokubo-Asari, a jailed militant leader.

“The purpose of this celebration of ability and capability was to prove to the armed forces of the Nigerian state that we can take them on anywhere, anytime and anyhow,” the Joint Revolutionary Council said in an email to journalists.

However, a spokesman for the Movement for the Emancipation of the Niger Delta wrote in an email to Reuters that the MEND had nothing to do with the attack.