Dili – Screaming "We are coming back for you", a gang armed with automatic rifles raided two villages in newly independent East Timor, killing four people and injuring eight, witnesses said yesterday.

The fighting late on Saturday and early yesterday in the villages of Tiarelelo and Laubonu – located about 60 km south-west of the capital Dili – prompted President Xanana Gusmao and Prime Minister Mari Alkatiri to fly there yesterday afternoon to meet residents.

Witnesses said they believed the 11 assailants belonged to pro-Indonesia militias, which wrought devastation in East Timor when the half island voted for independence in a 1999 referendum.

If their assertion proves true, the attack would be the most serious of its kind by militiamen since the country became independent last May.

East Timor's Foreign Minister Jose Ramos-Horta last month suggested that pro-Jakarta militiamen were behind a one-day riot that left two dead and dozens of buildings destroyed in Dili. Among the buildings burnt down was the home of Mr Alkatiri.

Yesterday, the Prime Minister suggested militias had become active in the country, though he stopped short of blaming them for the attack on the two villages.

"I believe that pro-Indonesia militias are still active," he said. "They are not trying to invade the country like in 1975 but they are trying to destabilise it."

Villagers said they had no doubt that the 11 men were pro-Jakarta militiamen. They said the men – all armed with automatic rifles – stormed into Tiarelelo, shooting indiscriminately and robbing villagers of money and food. A 17-year-old man was killed and three children were injured, witnesses said.

The gang then moved to the nearby village of Laubonu, where they killed the village head and his son, witnesses said. A third, unidentified villager was also killed, they said.

Villagers told Mr Gusmao that the gang had been active since November in the area. They said the same gang robbed a nearby village and kidnapped six people from another village. Only one of the six has been released.

"It is sad that so many people were killed," Mr Gusmao said. "But the killings will also serve to wake up the United Nations. Until now, the United Nations hasn't trusted the information that has come from the people. We have to stop these problems and bring these people to justice."