Beijing has claimed diplomatic immunity for a Chinese couple suspected in the shooting deaths of two Chinese diplomats and the wounding of the country's consul-general in the central Philippines, and will take custody of them, an official said Thursday. A Chinese man has been accused of killing diplomats Sun Shan and Hui Li and injuring Consul-General Song Ronghua on Wednesday in a restaurant in Cebu City, where they worked at Beijing's consulate. Police say the alleged attacker is the husband of another Chinese diplomat who has also been taken into custody. The Department of Foreign Affairs in Manila said Beijing has invoked the Chinese couple's diplomatic immunity under the 1961 Vienna Convention and a 2009 bilateral accord and has asked to take custody of them so they can be investigated and possibly tried in China. "The Chinese government would like to take custody of them and they will have to undergo the Chinese legal process," department spokesman Charles Jose said at a news conference. In Beijing, Foreign Ministry spokeswoman Hua Chunying said an investigation is under way to determine the motive for the attack and gather details. "We felt deeply distressed over this incident," she said at a regular news briefing. The 1961 Vienna Convention spells out protections afforded to diplomats and embassy staff, including immunity from local laws and criminal prosecution. China and the Philippines agreed in a 2009 accord that their consular diplomats enjoy those immunities. Jose said Chinese and Philippine officials are discussing the transfer of custody, which is to occur after a security team arrives from Beijing. The suspects are currently still in the custody of Philippine police in Cebu, about 570 kms (350 miles) south of Manila, at Beijing's request, he said. China has previously insisted on trying its citizens who have been accused of crimes in other countries. A Beijing court sentenced a Chinese man to life in prison in 2012 for murdering his girlfriend in Canada. In 2011, a Shanghai court handed a 15-year prison term to a Chinese man who admitted he killed a taxi driver in Auckland. In Wednesday's shooting, initial reports differed on whether the man or the woman was the suspected attacker but Jose backed police findings, based on witnesses accounts and security camera video at the Cebu restaurant where the shootings happened, that the husband allegedly fired the shots. "The shooting was an extreme act of a relative of a staff of the consulate," Jose said. Police Chief Superintendent Prudencio Tom Banas said the couple has not issued any statement that could explain the motive for the shooting, partly because they could not speak English. The victims and the suspects were attending a birthday lunch in a private room at the Lighthouse restaurant when the shooting occurred, Banas said. Citing witnesses and video from a restaurant security camera, Banas said the gunman first fired at the consul-general and his deputy, Sun Shan, in the room. Hui Li, a finance officer, ran outside the room but the attacker followed and shot her, he said. Investigators found that the Colt .45 pistol used in the attack may have been illegally obtained. A similar gun with the same serial number and an expired license has been seized from a Filipino owner in metropolitan Manila, police said. Attacks on diplomats are unusual in Asia. In September a South Korean court sentenced a man described as an anti-US activist to 12 years in prison for slashing and seriously injuring the US ambassador last March. — AP