The chairman of a Hong Kong university used as a base by radical protesters during a two-week battle with police said the institution was facing immeasurable losses to its research. Lam Tai-fai, council chairman of Polytechnic University, made his comments after a 13-day police siege of the campus ended on Friday. PolyU is expected to announce an estimate of its losses next week, and Lam said it aimed to resume classes in mid-January. “The loss of hardware can be resolved by money,” Lam told a radio programme on Monday. “But we are very worried that we cannot measure the loss in our research. We also don’t know whether it can be carried out again.” He said the suspension of some research projects, which were being carried out in university labs, might result in inaccurate findings. “The mice [in the laboratories] didn’t eat in the past week, what will happen? They are used for research,” he said. “If they have been starved for a week, will the research be affected?” However, when approached by the Post , Lam said he did not know further details of research projects that had been affected. Police surrounded the institution and stopped any frontline radicals from leaving without facing arrest on November 17, after one of the most intense and fiery battles in more than five months of anti-government protests. The demonstrations were triggered by opposition to a now-shelved extradition bill that would have allowed the transfer of suspects to mainland China. During the two-week stand-off, campus facilities were wrecked and laboratories broken into. Using chemicals and fuel they had collected, protesters made petrol bombs and other explosive and corrosive items. So far, police have found about 4,000 petrol bombs. Hong Kong universities need to consider restricting entry: education minister Lam said many labs were damaged and chemicals stolen, and added that repairs to the university were not simply a matter of clearing rubbish and replacing smashed glass. “We are not sure whether there are any structural problems with glass [in the campus] … whether there are any leaks of electricity and water, and any concerns over gas supply and the quality of water and air,” he said. University president Professor Teng Jin-guang had said earlier the government should pay for the major part of the cost for repairing the campus. Lam said on Monday that was necessary as the university had become a lightning rod for protesters’ dissatisfaction towards the government. Among more than 1,100 people arrested after leaving the site, only 46 were registered students at the university, according to police. “We are really innocent,” Lam said. “We know clearly that the target of the attack was not Polytechnic University or staff and students of the university, but the government,” he said. “Because of the government’s administration and governance, and its relationship with the public, we became a scapegoat. “It would be unreasonable if we had to bear all these costs.” Education sector lawmaker Ip Kin-yuen agreed that it would be logical for the government to bear most of the repair costs. “[The damage] this time was caused by confrontations, which were prompted by mistakes of government measures and clashes between police and civilians,” Ip said. “That was not something the university could control.” He said the government should also bear the costs of repairs at other universities which suffered damage amid protests over the past few months. City University revealed on Saturday that repairs and restoration of facilities would cost a nine-digit figure. It was the first of six universities which were damaged during recent anti-government protests to provide an estimate of such costs in a public statement.