Nigeria's last prominent militant leader agreed to halt fighting in the oil-producing Niger Delta and surrendered his weapons Sunday in return for an unconditional pardon.

Government Ekpemupolo, also known as Tompolo, whose gunmen were behind many attacks on the oil industry in the western Niger Delta, handed over rocket launchers, machine guns and explosives to Defense Minister Godwin Abbe at his camp in Oporoza in Delta state.

"It is an act of patriotism that Tompolo and his group surrendered their arms," Abbe said at the ceremony. "The time has come for us to settle down and find solutions to what led to the crisis in the region.

"Today marks the beginning of the development of the Niger Delta," he said.

Despite being home to Africa's biggest oil and gas industry, the delta is one of Nigeria's poorest regions.

Late Saturday, Tompolo accepted President Umaru Yar'Adua's amnesty offer, which was to expire at midnight Sunday.

Two commanders in the eastern delta, Farah Dagogo and Ateke Tom, laid down their weapons Saturday.

Politicians, security experts and residents hope the weapons surrender by the best-known militant commanders in the delta will bring stability, even if pockets of hard-liners still launch attacks.

The Movement for the Emancipation of the Niger Delta, or MEND, the umbrella militant group, warned Saturday that "unknown commanders" had replaced those who had accepted amnesty and that a next phase of its campaign would begin soon.

But the group has been severely weakened by the amnesty offer -- Tompolo was arguably its most important commander in the western delta and Dagogo a key leader in the east.

Thousands of people gathered in Oporoza and Warri to witness the disarmament ceremony.

Tompolo was short on words during most of the hand-over, able to say only, "All is well, all is well" to the crowd before bursting into tears.

"We came because we want peace," said Chief Andrew Anegba, who was among the thousands gathered in Warri to greet Tompolo before the ceremony.

Yar'Adua's amnesty offer is the most concerted effort so far to bring peace to the delta.

Unrest in the region has prevented Nigeria, which vies with Angola as Africa's biggest oil producer, from pumping much above two-thirds of its production capacity. It also costs the country $1 billion a month in lost revenue, according to the central bank, and has helped to push up global energy prices.

Despite Nigeria's oil riches, the vast majority of its 140 million people live on $2 a day or less, and some of the most acute poverty is in the villages of the delta. The militants say they are fighting for a fairer share of the oil wealth.