(AFP) Prime Minister Dr Mahathir Mohamad today warned foreign workers to abide the laws of the country following a riot by a group of Indonesians.

"Please go back to your own country (if you want to cause trouble), the premier was quoted as saying by Bernama news agency in the Kedah.

On Thursday some 400 Indonesian textile workers staged a violent protest in central Malaysia after police tried to detain 16 of their co-workers for drug abuse, police said Thursday.

The rioters overturned a police truck, van and a police car and then retreated to their five-storey hostel block from where they jeered at the police and threw chairs, tables, bottles and stones.

Ten Indonesian workers were eventually detained by police for suspected drug abuse after a tense stand-off and intervention by Indonesian embassy officials.

The incident took place in a textile factory in Nilai, Negri Sembilan.

Mahathir said the influx of foreign immigrants into the country could create an unhealthy situation in the employment sector.

"We must be careful. If many foreign immigrants work here, it would appear as if we are too dependent on them and in the end some of our employment sectors will be controlled by them," he said.

Screening needed

Zainal Rampak, president of the Malaysian Trades Union Congress (MTUC), told AFP that those who participated in the rioting should be charged and, if found guilty, punished and deported.

"Such wild behaviour must be nipped in the bud," Zainal said, adding that MTUC had warned the government that foreign workers must be screened to ensure only workers of good character were allowed in.

Zainal said the foreign workers in the country should be encouraged to join a union to avoid such incidents in the future.

"It (the riot) is a lesson to the company and others. If the workers are encouraged to join a union, their problems could be addressed without violence," he added.

Zainal said employers often stopped workers from joining a union out of fear that they would have greater strength to press demands.

No fresh arrests

Police said they had not made any fresh arrests following the riot but were monitoring the hostel were the Indonesian workers live.

"It's an international issue, so the authorities are having discussions to decide the fate of the workers involved (in the riot)," one police officer told AFP.

Last December, more than 2,000 illegal immigrants, including 1,560 Indonesians, went on riot at an immigration detention centre in Johor after being informed that they were going to be deported.

They set ablaze four blocks of buildings they lived in.

Malaysia has an estimated 700,000 foreign workers, mainly from neighbouring Indonesia, as well as hundreds of thousands of illegal immigrants.

Most of them are engaged in the low paying non-skilled sectors such as construction, plantation and the services.