Shell's output from Nigeria's onshore play has been heavily curtailed by violence, the Anglo-Dutch super-major Shell's chief executive Peter Voser said today.

"We have a huge proportion of our onshore production shut in at this stage," Reuters quoted Voser as saying.

"I think we are now at 120,000 barrels per day and we used to be close to 300,000 bpd. These are Shell's share (production)."

Violence in the Niger Delta, where Shell has long been a dominant player, has declined significantly since President Umaru Yar'Adua offered an unconditional pardon to militants in June, the news agency said.

However, activists said peace will only last if work can be found fast for those who have disarmed.

Voser said it was too early to say whether the improvement could be sustained.

"The overall security situation is still very fragile, the government had some success with their amnesty programme and we are looking now towards the next few weeks to see how this influences the whole security situation," Voser said.