International police and troops in East Timor were searching for rebel leader Major Alfredo Reinado after a mass jailbreak raised serious concern about fragile security in the fledgling nation.

Reinado, one of the figureheads of a revolt that plunged the former Portuguese colony into chaos in May, was among more than 50 prisoners who walked out of the Becora jail near the capital Dili on Wednesday.

The rebel leader said on a video tape obtained by Reuters Television that he did not want to stage a new revolt. "I have escaped from Dili not to revolt but because the judicial system in Dili is not good enough. But I will account for my action and answer any charges against me when the system has been improved."

Australian Foreign Minister Alexander Downer will fly to Dili on Sunday for meetings with Indonesian counterpart Hassan Wirajuda, as well as East Timor Prime Minister Jose Ramos-Horta and President Xanana Gusmao.

"It's obviously a matter of deep regret that this has happened," Mr Downer said. "It is going to be an important visit and in the light of the escape of these 56 prisoners, which is of very great concern to us, an opportunity for us to reinforce our support to the East Timorese."

Brigadier Mick Slater, the head of Australian troops in East Timor, said the prisoners walked out the jail's front gate during visiting hours.

Joao Domingos, head of Becora jail's administration, said grass cutters were used to intimidate guards during the breakout, in which he said all of Alfredo's men being held had escaped.

He said he was not aware whether guards helped in the escape. Another 148 prisoners remain in confinement. "They threatened us with grass shears. They said 'open the doors or you will die'. We opened the doors and 57 got away," Mr Domingos said.

The United Nations agreed last week on a new mission to East Timor, comprising some 1,600 police, despite a dispute over whether Australian-led international troops already there should remain independent or be part of a UN force. Mr Downer said the implementation of the new UN mission would be discussed at the trilateral talks, to be held on Monday.

City sealed off

Brigadier Slater said it was likely the escapees were now armed, although Dili remained quiet and calm after his troops quickly sealed off the city.

Dili suffered a series of protests that evolved into widespread violence in May after 600 members of East Timor's 1,400-strong army were sacked.

In late May, former military police commander Reinado led his followers into the mountains behind Dili and refused to give up weapons until then Prime Minister Mari Alkatiri resigned.

An estimated 100,000 people were displaced and at least 20 killed in the violence, which led to deployment of a 2,500-strong international peacekeeping force.

The revolt stemmed from divisions between troops from the east and those from the west of the country, which was ruled by Jakarta from 1976 until an independence referendum in 1999.