Twenty-five people have been killed in a fire on a foreign-flagged cargo ship docked at a port in eastern China, according to Chinese state broadcaster CCTV.

Of the 42 people on board, 17 were were evacuated of which five are in hospital in stable condition, CCTV reports.

The vessel was undergoing maintenance at a shipyard in the city of Qingdao when the blaze erupted at around 11:15 local time (03:15 GMT). It was put out just over three hours later, according to CCTV.

Photos released by state media showed the vessel to be the Ocean Melody, a 190m (623ft) long Liberia-flagged carrier which arrived in Qingdao on August 31, according to tracking site Marine Traffic.

Qingdao is a major trading hub and ranks among the world's busiest ports.

It is unclear what caused the fire. An eyewitness told the AFP news agency there was thick smoke rising from the ship, but he heard no explosion.

The country's leader Xi Jinping earlier called for "all-out" search and rescue efforts while Premier Li Qiang stressed the need to "prevent secondary disasters".

The fire comes nearly a month after a shipyard explosion in the south-eastern Chinese province of Fujian killed a rescue worker and injured 12 others.