SOFIA, Aug. 31 (Xinhua) -- Bulgarian ministers of the interior, transport and regional development on Friday resigned, taking political responsibility for the bus crash in which 17 people died on Saturday.

The resignations were requested by the country's Prime Minister Boyko Borissov, the Government Information Service said.

"We take the political responsibility. Obviously, we have not done well enough for this to happen. This is the short answer," Interior minister Valentin Radev said at a press conference.

"Probably the coordination between the departments under our leadership was not at the right level," said regional development minister Nikolay Nankov.

As many as 17 people were killed and 27 others injured in an accident in the Iskar Gorge near the town of Svoge, some 40 km north of Sofia, when a bus overturned.

The cause of the accident is under investigation. A mistake of the bus driver and poor state of the road are possible explanations so far.