The leader of Nigerian militants who captured four foreign oil workers said today he would not talk with negotiators sent by the government and reiterated threats to launch new attacks on oil installations.

Negotiators worked to free four foreigners held hostage in Nigeria’s southern oil region as militants claiming to hold the captives said they would target oil installations if their demands were not met within days.

Insurgents in Nigeria’s southern Niger Delta will begin “a full-scale armed struggle” to wrest control of the region’s oil riches from the government on Friday, a rebel spokesman said today.

Oil giant Royal Dutch/Shell has evacuated two platforms in Nigeria’s southern region, following clashes between troops and militia fighters.