BERLIN (AP) — An explosion outside an office of the far-right Alternative for Germany party in an eastern town has damaged windows and doors in the building, drawing condemnation from a senior regional official. No one was hurt.

Police told news agency dpa that an unknown substance exploded Thursday evening outside the office in Doebeln, in Saxony state — a stronghold of the party, known by its German acronym AfD, which entered the national parliament in 2017. Authorities were looking into the cause and possible motives.

Saxony’s deputy governor, center-left Social Democrat Martin Dulig, tweeted Friday that there is no justification for what happened, adding that “this attack helps AfD and damages democracy.” Saxony holds a state election in September.