Ujjain, Aug 23: Two labourers were killed and 36 others injured when their bus overturned in Madhya Pradesh's Ujjain district in the early hours of Sunday, police said.

The accident took place at around 3.50 am under Kaytha police station limits, some 20 km from the district headquarters, police inspector Pradeep Singh Rajput said.

The labourers, hailing from Etawah in Uttar Pradesh and hired by a contractor, were on their way to Ahmedabad, the official said.

As per initial investigation, the bus driver apparently dozed off when the vehicle was at a road turning. As a result, the vehicle overturned while negotiating a turn, he said.

A 24-year-old labourer died on the spot, while another 26-year-old victim succumbed to his injuries in hospital, the official said.

The injured labourers were admitted in different hospitals, he said.

"We have registered a case and further investigation is on," Rajput said.