BANGKOK -- Soldiers in full combat gear garrisoned the Thai capital's central business centre on Tuesday as thousands of anti-government protesters nearby threatened to disrupt Bangkok with a major rally. More offices closed and at least one hotel reportedly shut down temporarily in face of another possible eruption of violence and a dramatic drop in tourist arrivals. Leaders of the so-called "Red Shirt" protesters said they would stage an "important" demonstration Tuesday but did not disclose their specific plans. Prime Minister Abhisit Vejjajiva speaking on government-run television channels said he would not set a date for protesters to be forced out of their encampment at a busy intersection in the heart of Bangkok's shopping and hotel district. The demonstrators have camped out on the streets of the Thai capital since March 12. The Red Shirt protesters, formally known as the United Front for Democracy against Dictatorship, initially were camped in a historic district of Bangkok. A failed April 10 attempt by security forces to flush protesters from that neighborhood erupted into the worst political violence Thailand has seen in 18 years, leaving 25 dead and more than 800 wounded.