LAGOS, Nov. 23 (Xinhua) -- More than 400 pipelines have been destroyed in Nigeria's oil rich Niger Delta region in the last two years, the Lagos-based Vanguard newspaper reported on Monday.

Citing Joseph Dorgu, chairman of the Pipeline Professionals' Association of Nigeria (PLAN), the report said the vandalism was caused by militants in the region.

He said one way the nation could consolidate on the peace brought about by amnesty was to allow all sections to demonstrate integrity and transparency.

According to him, the action of the militant group was triggered largely by the absence of integrity in the system.

He added that the government should engage the employable group in the region, suggesting dialogue at all times in conflict resolution.

Dorgu also called for a strong electoral process that would produce popular leadership at all times in the country as another way to avert tension in the region.

The Niger Delta is an unstable area where inter-ethnic clashes are commonplace. Access to oil revenue is the trigger for the violence. Over 300 foreigners have been seized in the Niger Delta since 2006. Almost all have been released unharmed after paying a ransom.

Attacks and bunkering on oil pipelines in the Niger Delta have cut Nigeria's output by around a fifth in recent years, helping push world oil prices to record highs since the beginning of 2006.

The unrest in the region has forced many international firms to flee the area. The government mobilized the Nigerian army and coast guard in an anti-banditry operation.

In June, the Nigerian government offered amnesty to gunmen in the oil rich Niger Delta region, urging them to lay down their weapons by Oct. 4 in a bid to end unrest, which has cost Africa's top oil exporter billions of dollars in lost revenue.

More than 8,000 Nigerian armed youths gave up their weapons and embrace amnesty offered by the Nigerian government in the most concerted effort yet to end years of fighting in the oil-rich producing region.