At least 26 people have been killed and hundreds injured after a powerful earthquake in the Aegean Sea toppled buildings in the Turkish city of Izmir and created sea surges on at least two Greek islands, The Guardian reported.

Turkey’s disaster and emergency authority (Afad) said the quake, measuring about 7.0 in magnitude, struck at 2.51pm local time (11.51am GMT) on Friday. One of the dead had drowned, Afad said, while 709 people were injured.

Two people were reported to have been killed on the Greek island of Samos.

The death toll is expected to rise, with the mayor of Izmir telling CNN Turk that at least 20 buildings had collapsed in the city.

Afad put the magnitude at 6.6, lower than the US Geological Survey’s 7.0, while the European-Mediterranean Seismological Centre said the quake had a preliminary magnitude of 6.9.

The cities of Bornova and Bayrakli also suffered significant damage, the Turkish interior minister, Suleyman Soylu, tweeted.

Greek media reported rockfalls and some damage on Samos, where two teenagers died after being struck by a wall that collapsed, and 19 others were injured. The island, which is home to 45,000 people, including around 7,000 refugees, mostly consists of low-rise buildings.