One hundred and nine immigration detainees have escaped from the Lenggeng Immigration depot after setting ablaze their detention block at 9.45pm last night, police said.

Using aerial surveillance and tracker dogs, the authorities managed to capture 23 of them, said a Bernama report.

Negeri Sembilan deputy police chief Abdul Manan Mohd Hassan said

besides burning down a building, the group also rammed a nearby gate.

"We've set up a special team to determine how the fire was started. They made their escape via the oil palm plantation located behind the facility," he told reporters at the scene today.

He was confident that more escapees would be apprehended as they had only the dark forest cover to evade the authorities and, during the daytime, it would be difficult for them to access public transport due to road blocks, police cars patrolling the area as well as aerial surveillance.

 "Investigations show that they were dissatisfied with what they perceived as cramped living conditions, the food and long detention periods," he said.

Abdul Manan said it may well be that many of them had lost patience over the long process needed to settle them in third countries under the United Nations Refugee Agency (UNHCR).

"Some of them have been in detention for three to 12 months," he said.

The facility had 348 male and 192 women detainees at the time of the incident. None of the women were involved.

Four fire engines were at the scene to control the blaze. There were no reports of injuries.

According to AFP , Rusli Mokhtar, deputy commandant of the depot located just south of Kuala Lumpur, the undocumented migrants were "mainly from Myanmar (Burma) and Thailand" and had set fire to a detention block before escaping.

There are also Bangladeshis, Nepalese and Iranians. Police have mounted an operation to round up the others.

With one of Asia's largest populations of foreign labourers, Malaysia relies on its 1.8 million immigrants to clean homes, care for children and work in plantations and factories and on construction sites.

In March last year 16 migrants, including 12 Afghans, escaped after cutting their way out of a detention centre at Malaysia's main international airport.

Immigration activists say Malaysia is often used as a staging post for trafficking gangs moving people from Afghanistan and Burma to Indonesia and Australia.