At least 30 people were killed when two intercity buses collided in Pakistan's Punjab province on Monday, police said.The accident took place in Khanpur area, Dawn online reported. A police spokesperson said 55 other passengers were injured.The accident was so serious that the bodies of the dead and injured could only be recovered after cutting through the mangled vehicles, he said.One bus was on its way from Karachi to Lahore while the other was heading to Sadiqabad from Faisalabad.The cause of the accident is believed to be low visibility.