Smoke from burning buildings rose over the city as homes and shops were torched, and residents armed with crude weapons kept guard over their communities.

The governor of Maluku province, which includes Ambon, told the BBC that some of the rioters were killed by police when they opened fire to try to separate the warring groups.

Rageh Omaar: "Dozens of people have been left with horrific injurys"

He said other victims were trapped inside burning buildings.

The violence first erupted on Saturday in the town of Poka where many buildings were set on fire, and it has now spread to Ambon city.

By Tuesday morning it had even spread to the largest shopping centre in the Maluku provincial capital.

The violence that first erupted on 19 January has divided the island on sectarian lines.

Makeshift camps

Local people in Ambon, some 1,440 miles east of Jakarta, had expressed concern that some security forces were being withdrawn during a two-month lull in the violence. Many locals still fear revenge attacks by people on both sides.

Residents have fled the clashes by boat

Sectarian violence has killed at least 400 people this year in Indonesia, around half in Ambon. Tens of thousands of refugees are now living in makeshift camps across the vast region.

Tuesday was the third anniversary of one of the very first riots in Jakarta in 1996 which killed at least five people.