A Cypriot cruise ship is trying to rescue hundreds of migrants, most of them women and children, after their boat hit rough seas off Cyprus.

About 300 people, believed to be Syrian refugees, are thought to be on board the vessel 50 nautical miles (90 km) west of Cyprus.

The cruise liner Salamis Philoxenia was directed to the area to offer assistance after authorities picked up a distress signal from the boat this morning.

The cruise operator confirmed involvement but declined to comment further, saying the rescue attempt was under way.

"We estimate about 300 people are on board the boat, most of them women and children," a defence ministry spokeswoman told Reuters.

"They are on a small fishing boat and are possibly refugees from Syria."

Photos taken from a Cypriot army helicopter showed dozens of people sitting on the main deck of what appeared to be a fishing trawler being battered by rough sea and strong winds.

The condition of the boat's occupants was not immediately known. Cypriot authorities were making arrangements to receive and provide medical treatment to the migrants, the defence ministry said.