The presence of thousands of illegal immigrants in Sabah poses a security threat to locals, an activist said today.

"The problem is worrying. The government has to do something to correct the situation. All the illegals must be deported as soon as possible. They pose a security threat," said Patrick Sindu, the president of Sabah's consumer association.

There were up to 150,000 illegal immigrants in Sabah, said Misri Barham, the director of the state's Federal Special Task Force.

"The vast and long coastline makes monitoring and prevention of illegal entry of people into the state difficult," he was quoted as saying by the Bernama news agency.

Misri said in the first four months of 2007, the authorities had detained some 9,558 illegal immigrants in Sabah, mostly Filipinos.

Since 1990, they have arrested 348,086 illegal immigrants in the state - 192,653 Filipinos, 151,924 Indonesians and the rest from other countries, he said.

Sabah shares a border with Indonesia and is separated by the narrow Sulu sea from the Mindanao region in the southern Philippines, which shares cultural ties with Sabah.