Police in the southern Chinese city of Sanya are investigating 21 people who allegedly became violent during a cab strike Monday, a police spokesman said on Tuesday.

They reportedly attacked taxi drivers who would not participate in the strike and smashed 15 cabs, the spokesman told Xinhua.

All 21 could be charged with breaking the social security law and the regulations on complaints.

According to Xinhua reporters in the city, there were still few cabs operating in the city on Tuesday morning.

Sanya's Acting Mayor Wang Yong on Monday evening ordered local officials to resolve complaints from taxi drivers as soon as possible. Wang also said those involved in violence must be dealt with.

Wang expressed support for the establishment of a cabby association, which was one of the demands of striking taxi drivers.

More than 200 drivers gathered in front of the Sanya municipal government building on Monday morning, days after a similar cab strike in China's fourth largest city, Chongqing. Like that strike, Sanya's cabbies also demanded intervention on issues including high monthly taxi rental fees and unlicensed cabs.

There are about 1,200 licensed cabs running in Sanya, a major tourist city in south China's island province of Hainan. Those cabs are owned by six companies, taxi drivers said.

A driver, who only offered his surname as Zhang, said some companies ignored a municipal government policy which reduced drivers' monthly fees from 7,200 yuan (1,054 U.S. dollars) to an average of 5,300 yuan starting Jan. 1.

In addition, a large number of fee-dodging unlicensed cabs were operating across the city, further cutting into their earnings.

(Xinhua News Agency November 11, 2008)