Nigeria's main militant group began a unilateral ceasefire on Sunday after a week of clashes with the military and attacks on oil installations which have cut output in Africa's top producer.
The Movement for the Emancipation of the Niger Delta (MEND) launched strikes against pipelines, flow stations and other oil and gas facilities last Sunday in response to what it said were ground and air strikes by the military against one of its bases.
"We decided to 'stop outside Baghdad' even at a time of victory over the military and utter helplessness of the oil companies," the group said in an e-mailed statement.
"Effective 0100 hours (0000 GMT) September 21, exactly one week after we launched our reprisal, MEND will begin a unilateral ceasefire till further notice." Nigerian government officials have said production has fallen by 150,000 barrels per day (bpd) over the past week, and estimate the country's current output at 1.95 million bpd.
MEND said it had taken the decision after a plea by elders but warned it would restart its campaign if it came under attack from the security forces. It also warned that other groups aligned with it may not respect the ceasefire.
A spokesman for the joint military taskforce (JTF) which polices the Niger Delta cautiously welcomed MEND's announcement but said the group must demonstrate it could keep its word.
"We will continue to carefully and firmly monitor the situation, and exercise some level of restraint until their declaration is seen to have been actualised," Lieutenant-Colonel Sagir Musa told Reuters. "We are hoping it will not be another tactical deception which we have already prepared to contend," he said.