NEW YORK - Army chief General Ashfaq Parvez Kayanis first concern on hearing about the raid on Osama bin Ladens compound was Pakistans nuclear sites, The Wall Street Journal reported Monday. Gen Kayani was in his residential study in Rawalpindi when he was called about 1am to be told a helicopter had crashed in Abbottabad, the Journal reported, quoting a person familiar with Kayanis reaction to the raid. The source told the Journal that Kayani quickly concluded the helicopter must have been a foreign one that had breached Pakistani defences as Pakistani choppers seldom fly at night. The report said the general immediately was concerned for the safety of Pakistans nuclear missile installations, one of them being only a few dozen miles from Abbottabad. Kayani called Air Chief Marshal Rao Qamar Suleman, who scrambled two US-made F-16 fighter jets from a nearby air base, but the US choppers already were out of Pakistani airspace, the Journal said, quoting Pakistani officials. About 4 hours later, Kayani was informed on a secure line by Admiral Mike Mullen, chairman of the US joint chiefs, that a Navy SEALs team had flown deep into Pakistan, killed Osama bin Laden and returned to Afghanistan without alerting Pakistani authorities, the report said. Although the entire incident has embarrassed Pakistans intelligence service, US National Security Adviser Tom Donilon has said he has seen no evidence Pakistan was aware bin Laden had been living in Abbottabad for five years. The killing of bin Laden marked an epic victory for US forces. But for Pakistan military and intelligence network, it has meant national humiliation, the Journal commented.