Those who are critical have been referred to Kanpur.
The passengers were traveling to Bihar from Delhi to attend the festival of Chhath.
The accident took place in the Tirwa Kotwali area and all injured have been admitted in Tirwa medical college.
The festival of Chhath in Bihar attracts a large number of tourists every year to witness the three-day long festival. The bus which toppled at the expressway was carrying tourists for the festival.
(More details awaited)