This follows [1] violent protests against the proposed reopening of the one and only Orthodox seminary in Turkey. From [2] AFP, with thanks to Twostellas:

ISTANBUL, Oct 7 (AFP) - A home-made bomb damaged the seat of the Orthodox Church in Istanbul overnight but no one was hurt in the explosion, Anatolia news agency reported Thursday.

The device was lobbed over the wall around the patriarch's residence and exploded in the garden, blowing out several windows and damaging the roof of a nearby cathedral.

The ecumenical patriarchate in Istanbul is the Christian Orthodox world's highest authority.