Riot police also encircled demonstrators at Pearl Roundabout, the focal point of protests in Bahrain for nearly a month, firing tear gas canisters, while other protesters staged a number of marches on symbolic targets – the prime minister's office, the foreign ministry, and the state television building, among others. According to testimony collected by Physicians for Human Rights, riot police fired live shotgun ammunition into the crowd and beat protesters with batons and butts of guns.[4] Bahrain's interior ministry said eight police were injured during the operation to disperse protesters, including removing tents.[53] A Pakistani construction worker, Irfan Muhammad suffered serious brain injuries after he was allegedly brutally assaulted and had his tongue cut out by anti-government protesters.[54] A licensed Bahraini nurse reported treating five patients at the Salmaniya Medical Complex for gas inhalation on the night of 13 March. She reported that the patients' symptoms were consistent with nerve gas.[4] A primary care physician at a different hospital reported to Physicians for Human Rights reported that the medical center where she worked treated 26 patients for birdshot wounds and gas inhalation, also on 13 March.[4]