The leader of Thailand's anti-government protests says he has met with Prime Minister Yingluck Shinawatra and refused to back down from his movement's demand that her administration step down in favor of an appointed council.
Suthep Thaugsuban told supporters late Sunday at one of the protest encampments in the capital, Bangkok, that the meeting was held under the auspices of the military, which says it is neutral in the conflict.
Earlier Sunday, Thai police fired tear gas and water cannons against stone-throwing protesters trying to storm the Government House complex which houses the prime minister's offices.
It was the first police use of force since the demonstrations against Ms. Yingluck's government began a week ago. The government has urged Bangkok residents to stay indoors overnight for their safety.
The demonstrations had largely been peaceful, but tensions rose late Saturday and early Sunday after rival groups clashed in a northeastern Bangkok neighborhood where a large pro-government rally was being held in a stadium. Dozens were wounded, and unidentified gunmen shot and killed four people.
Later, an estimated 30,000 people tried to force their way into the government's heavily-fortified headquarters, took control of a state broadcaster and occupied Rajamangala University.
Ms. Yingluck left a Bangkok police complex Sunday to an undisclosed location and canceled an interview with reporters after demonstrators attempted to break into the compound.
Several of Bangkok's biggest shopping malls closed as a precaution against the violence.
Protest leader Suthep has urged government workers to strike Monday. His comments were televised live on all almost every station including state-owned Thai PBS, which agreed to broadcast the speech after protesters surged into its compound.
Opposition leaders have proposed an alternative to the country's democracy - a vaguely defined people's council made up of representatives from many professions - and vowed to take over every ministry until Ms. Yingluck resigns.
The prime minister survived a no-confidence vote in parliament Thursday. She refuses to quit and has called for dialogue to resolve the situation.
The conflict pits Bangkok's urban middle class and royalist elite against the mostly poor, rural supporters of Ms. Yingluck and her billionaire brother, Thaksin Shinawatra, a former prime minister ousted in a 2006 military coup.
The latest demonstrations were triggered several weeks ago by an amnesty bill that would have allowed Thaksin to return home and avoid a two-year jail term for corruption. The Senate rejected the bill but protests have continued.
The street protests are the largest in Thailand since 2010, when more than 90 people were killed in a military crackdown on an opposition protest.