Vaudine England, Jakarta – Men in Indonesian military uniform have been filmed providing covering fire for Muslim fighters as they attacked a Christian neighbourhood in the violence-wracked Maluku Islands. The footage has highlighted Christian calls for foreign troops to intervene, but such a move would be politically dangerous for President Abdurrahman Wahid.

Yesterday he suggested Jakarta could seek outside help if the fighting worsened, and Foreign Minister Alwi Shihab said such a deterioration could lead to the deployment of foreign troops – though he called such an outcome hypothetical.

The Muslim militants shown on the film with homemade weapons and army-issue Garand M1 carbines and Colt M-16 rifles. They also carried the SS-1, an Indonesian version of the Belgian-made FN 5.56mm automatic rifle, which is only available to army troops in Indonesia.

Another shot shows a Muslim fighter dressed in white with an orange headband, shooting an M16 through a bunker. M16s are also only legally available through the armed forces. The footage appears to provide the first firm evidence of the participation of Indonesian soldiers in a communal conflict that in 18 months has claimed about 4,000 Christian and Muslim lives. The men in military uniform, filmed from the Muslim side of a street battle in Ambon, could be heard speaking Javanese.

The Muslim fighters wore either white head gear or green head bands. They are thought to be members of the Laskar Jihad, a militant Muslim group that has sent at least 3,000 fighters to the Malukus.

Muslim mobs, aided by army soldiers, yesterday resumed attacks on Christian homes, a witness in Ambon said, adding that soldiers and "jihad forces" also had attacked two Christian areas on Sunday. Sammy Weileruni, of the Christian co-ordination post at the Maranatha church in Ambon, said witnesses had seen the soldiers briefing the attackers before Sunday's assaults.

Fighting has increased in Ambon and further north on the island of Halmahera, which Christian groups blame on the arrival of Laskar Jihad. They are calling for foreign troops to separate the warring sides given the inability of Indonesian troops to restore peace even under a recently declared state of civil emergency.

Mr Wahid said yesterday that "if the outcome is still not satisfactory after we have done our best, we may ask for international help in the form of equipment and logistics". Mr Shihab said: "If the Government and the TNI [Indonesian armed forces] cannot stop the bloodshed in the Malukus or at least get it under control then we will consider sending foreign peacekeepers – but such a situation now is merely hypothetical. We are doing our best to stop it."

US Defence Secretary William Cohen spoke about the Malukus while on a visit to Australia. "We would co-ordinate very carefully in terms of what responses would be appropriate, but that is something I think Australia must look at very carefully," Mr Cohen said.

Any armed intervention, and especially any led by Australian troops, would call to the Indonesian mind the events in East Timor last year when a foreign force stopped Indonesian-backed militia rampages. That affront to Indonesian pride was so great, and belief in a Western conspiracy to divide and rule Indonesia so widespread, that foreign intervention in the Malukus would be a threat to Mr Wahid's tenure in office.

Observers from both Muslim and Christian sides say the conflict in the Malukus is impossible to stop when the soldiers sent there to enforce peace are themselves participants on both sides of the religious divide. Defence Minister Juwono Sudarsono, in his most outspoken criticism yet of his own troops, said in a weekend newspaper interview that rogue officers were an "uncontrollable factor" in the bloodshed and urged their sacking. However, he said he was powerless to force the army to sack them.