All 29 former SMRT bus drivers from China who took part in last week's illegal strikes have been repatriated, said the Home Affairs Ministry.

They were placed on flights on Sunday between 12.15am and 4.35pm.

A statement said "they were co-operative and the process took place without incident".

Chinese embassy officials, as well as SMRT staff, assisted in the exercise.

The 29 had earlier got a stern warning from the police and their work permits revoked.

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

About 150 other drivers who had taken part in the strike will be warned and no further action taken against them.