Anti-government protestors on Thursday appealed to the European Union's office in Bangkok to send observers to their demonstration site to prevent "an imminent military crackdown." The "urgent appeal" to EU Ambassador David Lipman was written by United Front for Democracy Against Dictatorship (UDD) chairman Veera Muksikapong and delivered by three UDD supporters, according to dpa. "As a respected international organization, we appeal to you to assign representatives to monitor the government's actions," the letter said. "Faced with the threat of tanks and impending bloodshed, we are appealing to your help in averting a human rights catastrophe." The UDD has been occupying Bangkok's prime commercial district around Ratchaprasong Road since April 3. They have been staging protests in Bangkok since March 12, calling on Prime Minister Abhisit Vejjajiva to dissolve parliament and hold new elections. Although the protests were initially peaceful, they turned more confrontational in April, prompting the government to put the capital under emergency decree that effectively outlaws large gatherings and grants authorities some immunity in cracking down on the protests. So far, 27 people have died in protest-related violence with the latest clash occurring Wednesday when troops used barricades and rubber bullets to prevent 2,000 UDD followers from leaving Bangkok for neighbouring Pathum Thani province to stage a demonstration there. The highway showdown left one soldier dead and 18 civilians wounded. Private Narongrit Sala was shot in the head while riding a motorcycle toward government troops, suggesting he was killed by friendly fire. Government sources said they were still investigating the case. Abhisit, who came to power via a parliamentary reshuffle in December 2008, is under increasing pressure to end the protest or resign and dissolve parliament. On Thursday, leaders of the pro-government People's Alliance for Democracy (PAD) delivered a petition to Abhisit demanding that he rapidly settle the political crisis. UDD protestors number 5,000 to 30,000 at Ratchaprasong, the perimeter of which has been barricaded with tyres and sharpened bamboo sticks, making a crackdown difficult. When the government sent troops to clear UDD followers from Phan Fa Bridge, their previous protest site, in mid-April, a bloody street battle claimed 25 lives, including five soldiers, and left more than 800 wounded. Abhisit has alleged that "terrorists" working within the UDD used military weapons such as grenade launchers against the troops. Of the 20 civilians killed in the melee, many had been shot, either by snipers or soldiers. On April 22, five grenades launched at government supporters killed one woman and prompted more government accusations of terrorist tactics by the demonstrators.