Five children aged between 10 and 14 were injured in northern Austria on ​Saturday evening when a "war relic" that ‌was under their campfire exploded, police said on Sunday.

The children were part of a group visiting from another ​part of the same state of ​Upper Austria. The accident occurred in an ⁠area of the village of St Oswald ​bei Freistadt, where organised youth groups often camp, ​a spokesperson for the state police said.

After the explosion, police inspected an adjacent fire pit and found another ​object containing explosives that they also described ​as a "war relic", and a bomb disposal unit was called ‌to ⁠deal with it, police said in a statement.

"Investigations are currently underway to determine how war relics came to be under the campfire area," ​the statement ​added.

The severity ⁠of the children's injuries was not immediately clear, the police said, ​adding that they had been taken ​to ⁠a children's hospital in the nearby city of Linz.

While World War Two-era bombs are still uncovered ⁠in ​Austria, particularly in the course ​of excavations for building work, accidents such at Saturday's are ​rare.

- Reuters