Gunmen kill four soldiers, kidnap two South Korean workers in Nigeria oil region

Six people, including four soldiers, were killed while two South Korean employees were kidnapped after gunmen ambushed their convoy in Nigeria's oil-producing Niger Delta, a security source and the army said on Wednesday.

Attacks by militants in the Niger Delta have significantly decreased over the years but the region remains volatile and suffers from crude oil theft and vandalism of pipelines, which has hurt Nigeria's oil output.

Danjuma Jonah Danjuma, army spokesperson for Nigeria's 6 Division, said troops on routine escort duty for an oil-servicing company in southern Rivers State were attacked by suspected militants on Tuesday.

"Unfortunately, four soldiers were killed in action, with two other oil workers unaccounted for," Danjuma said in a statement.

A security source told Reuters that two civilian drivers had also died in the attack, adding that the unaccounted for oil workers were South Korean nationals.