Anti-government protesters exercise today in the compound of Government House in Bangkok, Thailand. Prime Minister Samak Sundaravej said Friday he won't negotiate with a radical group that has occupied his office in a bid to oust him.

Bangkok, Thailand ? Thai police warned students Friday to avoid street protests after a gunman shot and wounded two students demonstrating against the embattled prime minister, raising new fears of violence in the country’s tense political crisis.

The attack came after Samak proposed a national referendum Thursday to decide his political fate, a compromise dismissed by critics as a stalling tactic.

About 100 students were marching to demonstrate outside Samak’s home in the capital, Bangkok, late Thursday when an unidentified gunman on the back of a motorcycle opened fire on the crowd, said police chief Col. Somsak Bunsaeng of the Ladprao station in northeast Bangkok.

One of the students was shot in his left leg, the other in his left arm. Police said they were hospitalized but were not seriously hurt.

Anti-government protesters have occupied Samak’s official headquarters, Government House, for 11 days, vowing not to leave until he resigns.

The protests are led by a loosely knit group of royalists, wealthy and middle-class urban residents, and union activists. The alliance wants Parliament to be revamped so most lawmakers are appointed rather than elected, arguing that Thailand’s impoverished rural majority is too susceptible to vote buying.

Samak imposed a state of emergency Tuesday after his opponents and supporters clashed near Government House in rioting that left one person dead and dozens wounded.

Shooting incidents are rare in Bangkok, which was calm Friday with business going on as usual in most of the city. Anti-government protests have mostly been isolated to the area around Government House.