LAGOS -- The death toll from a Nigerian armoury explosion topped 1,000 on Saturday as signs of crumbling appeared in a police mutiny that has compounded the woes of Africa's most populous nation.

Searching continued for a sixth day in grimy canals to find those killed in a stampede to escape from blasts last Sunday which also made thousands homeless and sent military tempers soaring in a key barracks of the coup-prone country.

"We have almost completed the search for the bodies in the swamp," Lagos State Governor Bola Tinubu told Reuters. "More than 1,000 in total have been registered as dead."

An official inquiry has begun into the cause of the blast, which sent rockets, bombs and shells flying into heavily populated districts of Africa's biggest city, panicking residents who thought it was a military coup.

A group of human rights lawyers said on Friday that they suspected political sabotage might have been the cause, rather than an accidental fire which soldiers at first suggested had set off the blast.

Nigeria is struggling with its worst cycle of violence in 30 years and preparations are beginning for 2003 general elections in a country torn by ethnic and political rivalries.

Amid the unease and facing one of the most critical moments of his rule, President Olusegun Obasanjo gambled on ordering troops to take over key law and order duties from striking police, to stop Nigeria falling into anarchy.

The gamble appeared to be paying off on Saturday as many police in Lagos donned uniforms and returned to the job. Some also returned in southeastern cross river state, where the first police strike since independence in 1960 began.

Ringleaders Arrested

"The ringleaders have been arrested," assistant inspector General Sunday Gabriel Ehindero, police commander in Nigeria's southwest, told Reuters. "The fact is the others are returning to work. They are here. You can see them."

A police spokesman said four ringleaders had been arrested at the central town of Makurdi for distributing tracts throughout the country urging their colleagues to mutiny.

Nigeria paved the way on Friday for the biggest deployment of troops since military rule ended in 1999, though there was little sign of soldiers taking on police duties on Saturday.

At the same time Obasanjo approved the immediate release of funds for outstanding police salaries, but said payments would be jeopardized where the mutiny was not called off.

"We hear our grievances are being addressed. That is why I am returning to work," said policeman Michael Alapa in Lagos.

Nigeria suffered years of coups and decline under corrupt army regimes before Obasanjo's election in 1999, but a strike by police would have been unthinkable during military rule.

Since the return to civilian administration, rising crime has overwhelmed police, pushing some states to set up vigilante groups. Scores of police officers have been convicted of robbery or aiding bandits over the past year.

The feeling of insecurity was stoked by the mystery assassination of justice minister Bola Ige in December and further inflamed by the munitions dump blast.

The army sealed off the Ikeja barracks to outsiders on Saturday so experts could continue controlled explosions to destroy unexploded bombs.

Thunderous explosions on Friday sent a new shiver of fear through the city.