A Nigerian millitant group that has been targeting oil installations and pipelines in the country has declared a 60-day ceasefire after its rebel leader was set free under a government amnesty deal.
The Movement for the Emancipation of the Niger Delta (MEND) has carried out attacks on installations run by Shell, Total, Chevron and others, often crippling the country's oil and gas industry.
The group was also responsible for the kidnap of dozens of foreign oil workers, including several Britons.
On Monday Henry Okah, believed to be the leader of MEND operations, was set free after spending two years in jail following his arrest over weapons and treason charges.
Recent attacks by MEND have forced Shell, Chevron and Italy's Agip to cut oil production by about 300,000 barrels per day in the past six weeks, leading to rocketing oil prices.
The rebels launched their offensive in 2006, demanding that local people received a larger stake of Nigeria's oil wealth.