Philippine police Saturday detained a dozen airline passengers, said to be Chinese, after an alleged mid-flight scrap with a brother-in-law of President Benigno Aquino, officials said. The suspects, described by police sources as Chinese citizens, flew to Cebu on a domestic flight that also carried Aquino\'s elder sister Maria Elena Cruz and her husband Eldon Cruz, airport manager Nigel Paul Villarete said. Cebu airport police detained the suspects on the Cebu Pacific flight\'s arrival from Manila after the pilot filed a complaint, the manager told reporters. \"We are monitoring the investigation,\" Villarete added. Police sources in Cebu said one of those under investigation grabbed the presidential-in-law\'s neck to choke him when the latter asked the group to tone down their voices in mid-flight. Two of those under investigation are women, the police sources said. Chinese embassy spokesman Sun Yi did not return enquiries by AFP in Manila.