Austrian security services are investigating a series of blasts potentially aimed at Jehovah's Witnesses, after the car of a member of the religious group was set on fire on Friday, according to police.
Witnesses to the incident in Premstätten in the southern state of Styria reported "a kind of explosion."
As with previous incidents, no-one was injured.
Last August, bombs detonated in two Jehovah's Witnesses' cars, also in Styria, while their owners attended a prayer meeting.
At the end of March, a functional explosive device was found and defused in the entrance area of a meeting hall of the religious community in the state.
Jehovah's Witnesses say they have around 22,600 active members in Austria.