LAGOS, Nigeria (AFP) – Anglo-Dutch oil giant Shell has shut down a plant after militants raided its gas installation in southern Nigeria on Wednesday and kidnapped five South Koreans.

Nigerian authorities said at least three security force members died in the attack and four others were injured.

“The SDPC (Shell Petroleum Development Company) regretfully understood that there have been a number of casualties and that five Korean contractor staff (working for Daewoo and Kogas) have been abducted,” Shell said in a statement to AFP.

The Cawthorne Channel Gas Plant has been shut down pending assessment of damage, “resulting in the loss of some 70 million standard cubic feet per day of gas production,” the statement said.

The Movement for the Emancipation of the Niger Delta (MEND) said it attacked the southern Nigeria gas plant in response to a court decision earlier Wednesday morning to deny bail to guerrilla leader Mujahid Dokubo Asari. The group said it lost one man and had two casualties.

MEND said it was prepared to free the hostages in exchange for the release of Asari, the leader of the illegal Niger Delta People’s Volunteer Force, who was arrested in September last year and is standing trial for treason.