A detonator from a military mine is most likely to have caused the explosion at an orphanage in the southern town of Krumovgrad, which killed three children, prosecutors say.

“The explosive device most probably is a detonator from a military mine, which the children received from a servant at the orphanage,” District Prosecutor Svetlozar Lazarov told Darik Radio.

In his words the clues, collected by investigators, are pointing at the man, who is in charge with the local heating utility, as the main culprit.

According to unconfirmed reports the man has attempted to commit suicide a day after the tragedy and is currently hospitalized with a stab wound in his stomach.

The device went off around 2 pm on Saturday, killing three teenagers. One of the boys died on the scene while the other has been taken to the Krumovgrad hospital where he later died. A third boy was listed in critical condition in the hospital in the regional center – the city of Kardzhali, and died during surgery.

The victims Dzhingiz Rushen (13), and Sunay Keazim (16) are from the nearby villages of Pelin and Zimornitsa, while the third killed boy Dzhingiz Dzhemal (15) was born in the village of Sokolinovo, close to the southern border town of Momchilgrad.

The orphanage did not have security guards, which according to the mayor is a wide-spread practice, aiming to provide more serene environment for the children in the institution.

Forensic experts and members of the anti-terrorist task force are still scouring the site of the blast while psychologists are helping the other children cope with the tragedy.

Krumovgrad is a small, dilapidated and impoverished town, located close to the border with Greece. The border region is known to have been once strewn with mines and many of them are still buried in the ground.