Twenty-nine SMRT bus drivers from China yesterday received a stern warning from the police for their role in last week's illegal strike, had their work permits revoked and will be sent home.

The Government said one more driver will be charged tomorrow, bringing the total to five including the four charged last week.

The 150 other drivers who had taken part in the strike but "showed remorse over their actions, or were even coerced into participating" will be warned.

No further action will be taken against this group and they will be allowed to remain and work here, so long as they continue to abide by Singapore's laws.

"Barring any new developments, we do not expect further arrests or repatriations related to this illegal strike," said a joint statement from the ministries of Home Affairs and Manpower yesterday.

It described the strike last Monday and Tuesday as planned and premeditated, disrupting public transport, which is an essential service, and posing a threat to public order.

"While the SMRT bus drivers may have had grievances, these should have been raised through the legal and proper means available," it said.

At a press conference yesterday afternoon, Acting Manpower Minister Tan Chuan-Jin said the Government had been "very deliberate and very measured" in its response.

He said foreigners should abide by the laws of their host countries, just as Singaporeans who work and live overseas are expected to do the same.

While the Government acknowledged that many drivers took part in the strike "in the heat of the moment", and recognised that various grievances were raised, their actions remain illegal.

For the second time in a week, the ministry had strong words for transport operator SMRT. Mr Tan said it "could have done better" in managing the drivers' woes, and it must prevent such "a severe breakdown in labour relations" from occurring again.

"Companies should not allow labour grievances to fester... This is also a good and timely reminder, not just for SMRT, but for all companies to reflect on their management practices, the way they engage and look after their workers," he said.

Minister of State for Transport Josephine Teo, who co-chaired the conference, said the departure of the drivers will delay services slightly. Forty-five drivers from outside SMRT will be roped in to make up the shortfall.

The conference wrapped up an eventful week where labour relations and the hitherto unseen face of public bus drivers hit the headlines. The wages of foreign workers - especially doing jobs unpopular with Singaporeans - and how they are treated made it to the national conversation.

Last Monday, 171 SMRT drivers hired from China refused to board buses that arrived at their Woodlands and Serangoon dormitories taking them to work.

They told reporters they were unhappy with how SMRT bus drivers from Malaysia were paid better than them - $1,400 a month against their $1,075.

They were also disgruntled at conditions in their dormitories, with some rolling up their shirt sleeves to show bites from bedbugs. They also complained that SMRT had ignored and was insensitive to their complaints.

SMRT management met them for several hours till 6pm. The transport operator said it would get back to them in a week about their wage concerns, and the drivers said they would return to work.

Last Tuesday, however, 88 drivers continued to be absent. The Ministry of Manpower condemned their actions as an "illegal strike" - the first since 1986.

The strike ended last Wednesday. The next day, four drivers were charged under the Criminal Law (Temporary Provisions) Act, which states that anyone who instigates and incites others to take part in a strike or lockout shall be guilty of an offence. The Act covers strikes of workers from essential services, including public transport.

If found guilty, the four - as well as the fifth driver to be charged tomorrow - face a fine of up to $2,000 or a jail term of up to a year or both.

Meanwhile, the 29 drivers are being housed at the Admiralty West Prison while repatriation paperwork is being finalised. SMRT said they will be paid before they leave, including ex gratia bonuses on a pro rated basis.

The Chinese embassy here yesterday said it hopes Singapore will handle the matter "appropriately".