Injured suspect held over Revenue Tower attack Hundreds of people were forced to flee Revenue Tower in Wan Chai yesterday morning after an arson attack at a tax department public counter. Last night, a man suffering burns was under police guard in hospital after being arrested on suspicion of using flammable liquid to start a fire at a counter on the fourth floor of the tower. Security was stepped up at Revenue Tower after the attack. But civil service unions called for extra security at all open-counter government offices, saying they feared more abuse and violence as the economy deteriorated. The 51-year-old suspect was nabbed at Tuen Mun Hospital yesterday afternoon when he sought medical treatment hours after the fire. Police had alerted all public hospitals to watch for anyone seeking treatment for leg burns after a man identified as the attacker was seen fleeing the building with his trousers on fire. The attack happened at about 9.40am when a man approached payment counter No 5 at the Inland Revenue Department's Business Registration Office, where there were about 10 clients. 'The man poured inflammable liquid onto the counter, used a towel to wipe it and then used a lighter to set it alight before running away,' said Chief Inspector Ng Yeung-yin of the Wan Chai district crime squad. Police said the act lasted less than a minute. 'He did not say anything. He did not argue with the staff. We don't believe he's known to any staff members of the Inland Revenue Department,' Wan Chai district commander Chief Superintendent Blake Hancock said. More than 500 people were evacuated from the office tower. Mr Hancock described the fire as serious and said it was fortunate no one apart from the attacker was hurt. 'Clearly it was premeditated. Whatever reason was in his mind, we don't know yet.' One witness said the man appeared to try to put out the flames with his hands before running downstairs. Three bystanders - two men and a woman, described by police as very brave - gave chase but he broke free, ran across Harbour Road and got into a taxi outside the Renaissance Harbour View Hotel about 200 metres away. Inside the building, the auto sprinkler system was activated and the blaze was put out before firefighters arrived. Officers seized a lighter and at least two bottles believed to have contained flammable solvent at the scene. The wall and windows at counters No 5 and 6 were blackened. Mr Hancock said a surveillance camera recorded the attack. Office workers were allowed to return to offices in the lower floors of the building around noon but several services were suspended. The department said services would resume today but the Business Registration Office would remain closed. Last night the suspect, identified only as Wu, was under police guard in the custodial ward of Queen Mary Hospital. No charges had been laid. Yesterday's fire brought back memories of an arson attack eight years ago at next door Immigration Tower, where a confrontation between abode seekers and immigration officers ended in an blaze that left two people dead.