Nigerian security officials say they are searching for the body of a former rebel commander who was killed yesterday in the coastal city of Port Harcourt.  Officials say he was shot by unidentified gunmen while playing soccer.

The murdered man, Saboma George, was a former commander of the main militant group, MEND.

The government says he was killed by rival underworld a gang. The police commissioner of Rivers State, Suleiman Abba, says it was the killers who took away his body.

But some think the government was complicit in the killing.

?Our government and our leaders are not sincere about peace returning to the Niger Delta,? said Onoengiya Erekosima, president of the Niger Delta Non-Violent Movement.  ?We gave them a proposal that will solve this problem so that nobody repeats it, but the government has refused to listen?.?

Erekosima says the government has failed on its promise not only to rehabilitate the militants who embraced the amnesty program, but also to improve security in the area.

?Whatever gangs there are ? the government is aware of all their activities, but they don?t want to do anything because they benefit from the crisis,? he added.

Nigerian officials deny the accusation.

Erekosima says he had encouraged the late militant leader to drop his arms and accept the government?s amnesty program.

The killing has raised tension in the state, with colleagues of George upset over his death, says Erekosima.  The incident is renewing fears that violence in the oil-rich region will escalate.

?It happened very close to one of the police stations that  was attacked before by gangs and no officer responded to the shooting," said Erekosima. "Most of the militant leaders are planning to do something but we are talking to them to take the path of peace.?