A Singapore court on Thursday sentenced two Chinese workers to four weeks in jail each for staging a high-rise protest atop construction cranes in December, local media reported.

Zhu Gulei, 24, and Wu Xiaolin, 47, were sentenced after pleading guilty to a charge of criminal trespass when they clambered atop two tower cranes at a building site, the Straits Times and Channel NewsAsia said on their websites.

There was no immediate confirmation available from the court concerned. Foreigners jailed for crimes in Singapore are normally deported at their end of their sentences.

Zhu and Wu were the latest Chinese workers to be punished for defying strict laws against protests and industrial action in Singapore, a city-state that is heavily dependent on foreign manpower to sustain its economic growth.

Last month, four Chinese bus drivers were sentenced to jail terms of up to seven weeks after they pleaded guilty to instigating Singapore's first strike in nearly three decades.

Another Chinese driver was earlier sentenced to six weeks in jail while 29 others were deported without facing trial after the drivers staged a two-day stoppage in November to demand higher pay.

Singapore's previous strike took place at a shipyard in 1986. Its strike-free environment has been a major attraction for overseas companies, but activists say some foreign workers are badly paid and live in substandard dormitories.