A fire on a cargo ship undergoing repairs at a shipyard in the northeastern Chinese port city of Qingdao has killed at least 25 people, with five others still missing, state media reported.

The vessel, identified as the 190-metre bulk carrier "Ocean Melody," sailing under a Liberian flag, had 42 people on board when the blaze broke out at around 11:15 a.m. local time, according to state broadcaster CCTV.

The fire was extinguished at approximately 2:30 p.m. local time, roughly three hours after it started.

Twelve people were evacuated and five others were hospitalised in stable condition, CCTV reported. Death toll figures varied across early reports, with some sources citing at least 20 killed and others reporting at least 25.

The ship was docked at Beihai Shipbuilding Co. in Qingdao, a facility operated by the China State Shipbuilding Corporation, one of the world's largest shipbuilders.

The cause of the fire remains unclear.

President Xi Jinping issued instructions calling for an all-out search and rescue operation and ordered an investigation into those who may bear responsibility for the incident. Xi also called on "all regions and relevant departments" to "draw profound lessons from this incident, thoroughly investigate and rectify all types of fire hazards."

Premier Li Qiang called for those trapped to be rescued and stressed the need to "prevent secondary disasters."