At least 27 people have been killed and many more injured after a bus carrying pilgrims to a religious gathering fell into a gorge in Pakistan, police and rescuers said on Thursday. The crash occurred near the capital Islamabad late on Wednesday night. Heavy smog which has reduced visibility on highways across Pakistan was apparently to blame for the crash, police say. Around 50 people were injured in the accident and were being treated at hospitals in the nearby city of Rawalpindi, rescue official Khurram Manzoor said. Bad roads, poorly maintained vehicles and substandard traffic safety regulations cause numerous accidents and more than 5,000 deaths in Pakistan every year, according to government statistics.