Grace Nirang, Jakarta – Life had returned to normal on the streets of Indonesia's troubled eastern city of Ambon on Sunday, police said, a day after a bomb blast that injured 53 people and may raise fresh doubts about a regional peace pact.

The count of 53 injured was raised from a figure of 51 given by an Ambon official on Saturday. Police said five of those were seriously injured.

Police said they were questioning six witnesses in connection with the bomb that went off in a Christian area near midday on Saturday. It was the latest violence in Ambon, the hub of the Moluccas islands where clashes between Muslims and Christians have killed at least 5,000 people in the past three years.

"Ambon so far is calm and under control. Christians are going to the churches as usual," police chief Noviantoro told Reuters from Ambon, some 2,300 kms east of Jakarta.

"It was a homemade bomb. We are questioning six people who witnessed the bomb blast," he said, adding that the bomb was planted in an ice cart in a busy market in Ambon. He said police data show most of the injured were students of nearby Pattimura University.

"Most of the victims have left the hospital. Five of the victims are seriously injured," he said. While a baby and a four-year-old girl were among the wounded, they were not suffering serious injuries, he added.

Another police officer said the bomb had gone off in a Christian neigbourhood, although some Muslim families had returned to live there after the signing of the peace pact. "Judging from their names, most of the victims are Christians," the officer said.

The bomb squad also found an unexploded bomb in a warehouse near the scene of the blast, police said.

Any major outbreak of violence on Ambon or elsewhere in the islands could threaten a landmark peace deal signed in February. The deal has held relatively well by Indonesian standards.

Leaders confident

But central government and local leaders said they were confident the latest violence would not ruin the peace process.

"Anything that happens in Ambon will no longer be able to provoke the people," Chief Welfare Minister Jusuf Kalla told reporters after a meeting with President Megawati Sukarnoputri on Saturday. Kalla led the peace negotiations between the warring sides in February.

Reverend Frans Lutherman of the Moluccas Advent Church said: "It was the act by outside groups. Christians and Muslims in Moluccas want an end of the violence. You can see that there is no response from the two sides on the attack." Most factions involved in the Moluccas islands fighting signed the peace deal in February, but tensions remain high and there have been sporadic outbreaks of violence.