THESSALONIKI, Greece (AP) — Greek authorities charged four men Monday over a weekend mob attack on the 75-year-old mayor of the country's second-largest city, carried out in an apparent venting of nationalist sentiment.

The suspects, aged between 17 and 36, were formally accused of grievous bodily harm and breach of the peace over Saturday's attack on Yiannis Boutaris.

The mayor of Thessaloniki required hospital treatment after being thrown to the ground, kicked and punched by about 12 people during a ceremony honoring Greek victims of mass killings by Turks during World War I.

The trial of the three adults will be held on Wednesday, after their lawyers requested a two-day deferral to better prepare the defense. The 17-year-old will appear before a court for minors, but no trial date has been set for him.

One of the suspects allegedly told police he was angry at a recent statement by Boutaris, a liberal centrist, favoring friendlier relations with Turkey. Another two have apologized, telling police that they were carried away by the behavior of the rest of the crowd.

Prosecutors are also carrying out a separate investigation into whether charges can be brought against so-far unidentified individuals for instigating the attack.