Officers from Greece’s anti-terrorism squad have arrested a second person in connection to a bomb explosion in downtown Larissa, central Greece, early Saturday.

Authorities said that a 44-year-old man was arrested in Athens on Sunday. He was known to the police and had been linked to incidents of blackmail in the past. His arrest followed that of a 39-year-old man near the scene of the blast, which damaged 19 buildings and several vehicles.

The explosive device had been placed outside an apartment block where a local prosecutor lives. The judicial official had been involved in cases relating to crime syndicate boss Panayiotis Vlastos, who recently failed in an attempt to escape from prison.

The blast came just a few hours after judges and prosecutors had written to the government to ask for greater protection.