A powerful earthquake shook the Greek resort island of Kos early Friday morning, damaging older and historic buildings and the main port, killing at least two people and causing more than 120 injuries, authorities said.

The 6.5-magnitude quake rattled other islands and Turkey’s Aegean coast as well, but Kos was nearest to the epicenter and appeared to be the worst-hit, with all of the deaths and injuries reported there.

A wall collapsed on a building dating to the 1930s and it crushed people who were at the bar in the building’s lower level, according to Kos Mayor Giorgos Kyritsis. “There are not many old buildings left on Kos. Nearly all the structures on the island have been built under the new codes to withstand earthquakes,” the mayor said.

Kos’s “old town” area, full of bars and other night-time entertainment, was littered with fallen bricks and other debris. The island’s hotels had broken glass and other damage, leaving hundreds of tourists to spend the rest of the night outdoors, resting on beach loungers with blankets provided by staff.

“The instant reaction was to get ourselves out of the room,” said Christopher Hackland of Edinburgh, Scotland, who is a scuba instructor on Kos. “There was banging. There was shaking. The light was swinging, banging on the ceiling, crockery falling out of the cupboards, and pans ... There was a lot of screaming and crying and hysterics coming from the hotel,” he said, referring to the hotel next to his apartment building. “It felt like being at a theme park with one of the illusions, an optical illusion where you feel like you’re upside down.”

Other buildings damaged included an old mosque where a minaret collapsed and a 14th-century fortress at the entrance to the main port. Coastal roads were flooded. Minor damage cracks in buildings, smashed windows and trashed shops appeared widespread.

Rescuers were checking for trapped people inside houses after the quake struck in the middle of the night and were heading to outlying villages to check for damage. Ferry service was cancelled until daylight because Kos’s main port was damaged.

Giorgos Halkidios, Kos regional government official, said the injured included people who were underneath a building that collapsed.

Greek officials said the quake was 6.5-magnitude and the numerous aftershocks were weaker but still could put at risk the buildings that were already damaged. The epicenter was 10 kilometers south of Bodrum, Turkey, and 16 kilometers east-northeast of Kos with a depth of 10 kilometers.

In Turkey, the ensuing panic caused minor injuries, according to Esengul Civelek, governor of Mugla province.

In Bitez, a resort town about 6 kilometers west of Bodrum, the quake sent frightened residents running into the streets.

Greece and Turkey lie in an especially earthquake-prone zone.