Militants in Nigeria's southern Niger Delta, whose campaign of sabotage has sharply cut the country's oil output, announced a ceasefire on Sunday but stopped short of agreeing to participate in peace talks.
The Movement for the Emancipation of the Niger Delta (MEND) declared the ceasefire just days after one of its most daring attacks so far, which forced Royal Dutch Shell to halt output from its main Nigerian offshore oilfield, Bonga.
"Effective 12 midnight on Tuesday, June 24, MEND will be observing a unilateral ceasefire in the Niger Delta region of Nigeria until further notice," the group said in an e-mailed statement.
"We are respecting an appeal by the Niger Delta elders to give peace and dialogue another chance," it said.
The bombing of oil pipelines and kidnapping of oil workers by MEND - mostly in the labyrinthine creeks of the Niger Delta - have cut Nigeria's oil output by at least a fifth in recent years, helping drive world oil prices to record highs.
Oil Minister Odein Ajumogobia said on Sunday the world's eighth largest oil exporter was producing around 1.8 million barrels per day (bpd) before the latest attacks, less than two thirds of its 3 million bpd installed output capacity.
The announcement by MEND - a loose coalition of armed groups with an ill-defined leadership - comes weeks before a peace summit called by President Umaru Yar'Adua's government.
Asked if the ceasefire meant it would take part in the summit, MEND repeated in an e-mail to Reuters that it would only do so if Henry Okah - one of its suspected leaders who is on trial for treason and gun-running - was allowed to attend.
No date has yet been announced for the summit and some analysts doubt it will achieve much given the fragmented nature of the militants and the lack of a cohesive strategy among Nigeria's federal, state and local governments.
SECURITY TIGHTENED
Last Thursday's attack on Bonga, which lies some 120 km (75 miles) from the Nigerian coast, was the first significant strike on a deepwater facility in the country and shocked an oil industry which had thought such sites relatively secure.
It forced Shell to stop production at the field, which has a nameplate capacity of 220,000 bpd, and to declare force majeure on Bonga exports for June and July, meaning it cannot guarantee to meet contractual obligations.
Nigeria's House of Representatives has called an emergency meeting for Monday with the defence and oil ministers, national security adviser and foreign oil firms to discuss the attack.
Yar'Adua has pledged a two-pronged approach in dealing with the delta, promising to address the under-development of the region, which lies at the root of the agitation, but also saying he will not tolerate the presence of armed militants.
He ordered the armed forces on Friday to bolster security in the delta and hunt down those responsible for the Bonga attack.
In response, MEND warned expatriate oil workers to leave the delta while it "settled its score" with the government, raising the prospect of an upsurge in violence in the region.
The group had called on Friday for local communities in the delta to sabotage oil facilities and on Saturday congratulated "patriotic youths" who it said had blown up a pipeline operated by U.S. oil firm Chevron last week.
The army said that attack had shut another 120,000 bpd of oil production.
