Matthew Moore, Jakarta – Masked gunmen who slaughtered eight Christians in Central Sulawesi over the weekend may have timed the killings to coincide with the Bali bombing commemoration then due to begin just hours later.

However, Indonesia's Co-ordinating Minister for Welfare, Jusuf Kalla, did not believe the attacks on four villages in Poso regency, about 1500 kilometres north-east of Jakarta, signalled a return to the bitter fighting between Muslims and Christians that left some 2000 people dead in and around Poso between 2000 and 2001. At least 9000 more were killed in similar violence in neighbouring Maluku islands.

Mr Kalla, who in December 2001 negotiated the Malino peace accords which brought an end to the Poso violence, said the carefully planned attacks were not carried out by people who were engaged in the old conflict.

"It was carried out by an armed group who attacked the people while the people themselves remained united," Mr Kalla was quoted as saying on Detik internet news service.

He said there was a view that the killings in the Christian-dominated area may have been carried out by sympathisers of the hardline Muslims who carried out the Bali bombings and a later bombing last year in a McDonald's restaurant in Makassar in South Sulawesi.

"There are those who believe it is connected to the verdicts in the Makassar bombings and [the attacks] were at the same time of the one-year commemoration of the Bali bombing," he said. "Indeed, there are coincidences."

Church leaders in central Sulawesi province fear the attacks on Christians could lead to a return of the bloody religious violence. "There have been many victims from our side," Ferry Naray, of the Central Sulawesi Protestant Church Crisis Centre, said yesterday. "Christian communities here are frightened."

Faisal Mahmud, of the Sulawesi branch of the Indonesian Muslim Clerics Council, said the attackers were "irresponsible people whose goal is to recreate instability in Poso." He doubted, though, that the violence would escalate, Police have declined to speculate on who might be behind the killings – the most serious violence there in two years.

The attacks, at 11.30 pm on Saturday, came just days after a similar attack on a Christian village that left two people dead and 27 houses and one church burnt to the ground.

The deputy police chief in Poso, Rudi Trenggono, said he believed the two attacks were carried out by the same group which had shot and stabbed people on both occasions. He did not know who was behind the attacks, but was certain they were not linked to any resumption of sectarian violence.

Police found 90 spent cartridges in the four villages attacked. He believed one house was burnt down to distract police and help the killers in other villages to avoid getting caught.