Story highlights A school bus went off the road and into a canal, police say

Seven children were declared dead at the scene, according to police

Of the dozens injured, 11 were admitted to a military hospital, a superintendent said

A bus carrying schoolchildren on a study trip skidded off a road and into a canal in southwestern Bangladesh on Saturday, killing at least seven children and injuring dozens more, a police chief said.

The seven children were between the ages of 6 and 12, and they were declared dead on the scene, said Joydev Khadra, the district police chief.

Of the injured, 11 were admitted to a military hospital in serious condition, said police superintendent Joydev Kumar Bhadra.

The bus was carrying 75 children who attended a primary school in the district, Khadra said. It was one of three returning from Mujibnagar, police said.

Bangladesh Prime Minister Sheikh Hasina ordered an investigation into the accident.