Singapore  -  An accused Islamic terrorist escaped from a top-security detention centre in Singapore via an improperly secured ventilation window in a bathroom, Deputy Prime Minister Wong Kan Seng said Monday.

Although Mas Selamat was escorted by two Gurkhas and an Internal Security Department junior officer, he managed to climb out of the window during the 11 minutes that elapsed between a trip to the toilet and the issuing of an alert, Wong told Singapore's Parliament.

His family was waiting for a visit in another room.

It has been seven weeks since the 47-year-old suspected leader of Singapore's wing of the Jemaah Islamiah militant group fled and triggered the biggest manhunt in the country's history, which has involved thousands of armed personnel.

No conclusion has been reached on the route he took, Wong said.

The deputy premier said the February 27 escape was planned but there was no collusion with anyone inside or outside the Whitley Road Detention Centre. This was the conclusion of several investigations, Wong said.

A new detention centre has been proposed near Changi Prison, and revisions are to be made in the escort procedures of detainees at Whitley Road.

All of the officers on duty at the time of the escape are to be dismissed, Wong said.

His explanation, which was the conclusion of an inquiry committee, sought to answer questions over how an escape could be carried out from such a high-security facility by a man with a limp.

The escape and subsequent failure to track Mas Selamat down in tiny Singapore generated public criticism and ridicule on the internet.

After the escape, security personnel were put on round-the-clock duty scouring forested areas and nature reserves, knocking on doors of homes, securing land and sea borders and guarding land, sea and air routes leading out of the country.

Hundreds of thousands of wanted posters were distributed to the public and plastered throughout the city-state.

Mas Selamat, accused of plotting to hijack a plane and crash it into Singapore's Changi Airport, was sent to Singapore in 2006 after his arrest by Indonesian police.

He was held in the centre under the Internal Security Act, which permits indefinite incarceration without trial.

Singapore sought the help of Interpol, and there were subsequent unconfirmed reports that Mas Selamat was sighted in Indonesia.

When the mass search failed, the Home Ministry switched tactics from large-scale operations to more focused ones based on intelligence reports. (dpa)