BANGKOK (AFP) - Thousands of Red Shirt demonstrators loyal to Thailands fugitive former premier Thaksin Shinawatra gathered in Bangkok Sunday to rally against the current government, police said. Crowds of red-clad protesters arrived mid-afternoon in the citys historic quarter, where a 1,500-strong police force was on hand to prevent violence, although they said they were expecting the event to be peaceful.Police estimated that around 6,000 demonstrators were present by early evening and said the number could reach 8,000. The rally is the latest in the three years of political turmoil which has rocked Thailand since a September 19, 2006 coup against Thaksin. The twice-elected billionaire lives in exile to avoid a jail term for corruption. Last month at least 26,000 Red Shirts took to the streets of the Thai capital to mark the third anniversary of the coup, demanding new elections and the resignation of current prime minister Abhisit Vejjajiva.Sundays rally was expected to remain smaller, without Red Shirts from Thaksins main support base in the north and northeast, and the state did not invoke harsh internal security laws that it has used against bigger protests. The next mass rally is planned for October 17. Red Shirt leader Jatuporn Prompan said the purpose of Sundays meeting was to demand the reinstatement of the 1997 constitution, which was scrapped after the Thaksin coup, and to kick off a campaign for the impeachment of Abhisit. There is evidence of widespread corruption in every ministry, he said. Thailand remains deeply divided between supporters of Thaksin, who are concentrated in rural areas, and his foes in the Bangkok-based power cliques of the palace, military and bureaucracy. On Wednesday around 5,000 anti-Thaksin Yellow Shirts rallied in Bangkok to mark the first anniversary of their violent clashes with police, when they marched on parliament in protest at the former governments ties to Thaksin. From late November, the royalist Yellows staged a crippling, 10-day seizure of Bangkoks two main airports, which effectively toppled the pro-Thaksin government and badly dented Thailands tourist-friendly image.