DAKAR, Senegal — Fourteen people were killed and 19 wounded when a bus carrying students ran over a roadside bomb on Saturday in northern Burkina Faso, the government said.

It was not immediately clear who was responsible for the blast, which hit one bus in a convoy of three that was carrying 160 passengers in all, the government said in a statement.

The incident occurred in Sourou province, near the border with Burkina’s chaotic neighbor Mali, where Islamist groups with links to Al Qaeda and the Islamic State have increased attacks over the past two years despite international efforts to stamp them out.

Three sources said earlier that the convoy had been ferrying pupils back from an end-of-year school break. The government statement said seven students were among the dead, without providing their ages.