ATHENS, Greece — Seven senior members of Greece’s Orthodox Church and three others were hospitalized with burns Wednesday after being attacked with a caustic liquid, allegedly by a priest facing a disciplinary hearing, authorities said.

The incident occurred at a meeting in Athens of senior bishops. The 37-year-old priest, who was facing the hearing for alleged drug-related offenses, was arrested unharmed and detained for questioning.

A police officer who helped restrain the suspect was also injured, as were a lawyer and a presiding clergyman. They were transferred to state hospitals, for treatment, and two clergymen were described as being in more serious condition.

Police said it was not immediately clear what liquid was used, but added that the victims were being treated for burns.

“I express my abhorrence at this unprecedented event,” Greek President Katerina Sakellaropoulou wrote in a tweet after contacting Archbishop Ieronymos, the leader of the Greek church.

Most of the victims hold the senior rank of metropolitan bishop

Health Minister Vassilis Kikilias visit an Athens hospital where the bishops were initially treated, joined by Archbishop Ieronymos.

Ieronymos told reporters he was “deeply saddened” by the attack but relieved that none of the injuries were considered by doctors to be life-threatening.

Health Minister Kikilias said four of the bishops were more lightly injured and were receiving first aid, while one was transferred to the plastic surgery unit of another hospital and the other two might also be transferred to other hospitals with specialized units, including one with a specialist eye clinic.

He said Prime Minister Kyriakos Mitsotakis had asked for constant updates on the case.

The motives for the attack were not immediately clear. State-run ERT television reported that the hearing was held as an appeal to depose the priest from the clergy.

Police identified the victims as the metropolitan bishops Antonios of Glyfada, Kyrillos of Kifissia, Kallinikos of Arta, Nikodimos of Kassandra, Dionysios IV of Zakynthos, Dimitrios of Goumenissis, and Andreas of Dryinoupolis.