Foreign workers seized in Nigeria

Attacks by militants on Nigeria's oil industry have escalated

Six Filipino workers have been kidnapped from a cargo ship in Nigeria's oil-rich Niger Delta region, security sources say.

They say the six were seized as the ship headed to the port of Warri.

Militants seeking a greater share of the region's oil wealth have been targeting foreign oil facilities and their workers since early 2006.

Nigerian President Olusegun Obasanjo has denounced the spate of kidnappings as the work of criminals.

In recent months attacks by the militants have escalated, causing oil multinationals to evacuate thousands of workers from the western side of the region.

Five Chinese telecommunications engineers were released on Thursday after being kidnapped from the Niger Delta region on 5 January.

The instability in the region has cut Nigeria's oil production by at least 20%, costing the country some $4.4bn (£2.2bn) last year, according to the government.