At least twenty people were killed while 30 others wounded when a bus fell into a ravine near Chattar Park on the outskirts of Islamabad Saturday night, police said. The bus was coming to Rawalpindi, near Islamabad, from Murree when it swerved near Chattar Park and fell into a gorge. Police said the passengers were returning from a religious congregation. The Rawalpindi and Islamabad administrations supervised the rescue operations after the accident.