Jakarta – The latest eruption of violence between Muslims and Christians in the eastern Indonesian city of Ambon has left up to 20 dead over two days, including a police major.

The state news agency, Antara, quoted Maluku military chief Brig-General Max Tamaela as saying that two army soldiers and two members of the elite police mobile brigade (Brimob) were killed when Muslims attacked police barracks in the Tantui area of Ambon on Wednesday. "I have received reports that four members of the security forces were killed in the clashes," he said.

Brig-Gen Tamaela said Major Edi Susanto, the deputy chief of Brimob was among the officers killed. Antara said Major Susanto was killed by a bullet that went through his hip. Two Brimob policemen were also injured. A worker at the Al Fatah Muslim hospital said 13 people were admitted with injuries, while three bodies were brought in.

Meanwhile, a Muslim cleric claimed that police attacked a boat carrying Muslims near Ambon yesterday. "Conditions heated up today after a mob of Christian police using three speedboats attacked a Muslim boat, killing two passengers and injuring 10 others," said Malik Selang from the Moluccas chapter of the Indonesian Ulema Council. "Up until now, six Muslims have been killed." No independent confirmation of the police attack was available.

Ambon, the capital of Maluku province, remained tense early yesterday as security forces fired shots to disperse clashing armed mobs of Christians and Muslims. Sounds of home-made bombs exploding were heard in several areas of Ambon and clashes were spreading to the centre of the city. Schools and offices were closed.

On Wednesday, Mr Sammy Weileruni, a lawyer for the Maranatha church support group, said thousands of Muslims attacked a police housing complex in Tantui, setting fire to two churches there.

He accused elements in the army of supporting the attackers through inaction. Christians have accused sections of the army of siding with Muslims, while Muslims have charged Brimob of bias towards Christians.

In the North Malukus on Wednesday, troops opened fire on armed Christians. The mob wanted to avenge the deaths of two Christians in an attack by Muslims on the island of Halmahera on Monday.

Meanwhile, Indonesia's Defence Minister Juwono Sudarsono said the armed forces and police were trying their best to control the situation and more troops were being deployed. However, he admitted it was hard to stop provocateurs and weapons from being smuggled into the area where more than 2,500 people have been killed in the past 18 months.

The United States State Department called for dialogue among followers of the two faiths and said it was "deeply concerned about the intensifying cycle of violence and retaliation".

Spokesman Phil Reeker said: "We're troubled that the security forces are unwilling or unable to stop large-scale attacks on communities, so we're urging Indonesia to take immediate and effective measures to prevent further bloodshed."