Dili – East Timor Prime Minister Mari Alkatiri said Wednesday that his country's police force had acted in self defence when they shot dead three former pro-Jakarta militiamen near the border.

He also criticised Indonesia for failing to prevent militiamen from infiltrating East Timor.

The incident Friday sparked a diplomatic row between Indonesia and its former province of East Timor, with Jakarta accusing East Timorese police of excessive use of force.

"Our policemen were ambushed by these three individuals that entered our country without documents, visas or passports," Alkatiri told a press conference.

One of two teenagers who managed to escaped the shooting said they and their three colleagues had intended to fish in a river near the border but had unwittingly crossed into East Timorese territory.

The three former members of the Red and White Iron militia took Indonesian citizenship after East Timor voted for independence from Jakarta in 1999.

Alkatiri said Indonesia has failed to prevent militiamen from infiltrating East Timor.

"Indonesia knows that it has people like this in its country. It is Indonesia's responsibility first of all to control those people, and to not allow them to cross the border and come here to provoke us," he said.

Around 1,500 mostly East Timorese who moved to Indonesia's West Timor after the 1999 referendum took to the streets of Atambua near the border on Monday to condemn the shootings.

Indonesian Foreign Minister Hassan Wirayuda described the incident as "an excessive use of violence" and urged East Timor to prosecute the policemen who carried out the shooting.

Pro-Jakarta militias, which the United Nations says were directed by the Indonesian military, staged a deadly campaign of violence against independence supporters in East Timor before and after the referendum

An estimated 1,400 people were killed by the militias and whole towns were destroyed.