WANA: Six schoolchildren were injured when their bus hit a landmine in Shakai Valley of South Waziristan on Monday, an official and residents said. Two students, between six and nine, were reported in serious condition in hospital, administration officials said in Wana, the regional headquarters of South Waziristan. The incident took place 35 kilometres northwest of Wana in Shakai Valley, which was a stronghold of militants before army operation in June 2004. "The injured students were from a school in Shakai," the officials said. "Two of them are serious," they added. Meanwhile, militants attacked the airport in North Waziristan causing some damage to runway, security sources in Miranshah said. A rocket landed on the runway at 1.30am on Monday, damaging it mildly.