A Hoegh Autoliners car carrier has suffered a fire and an explosion while alongside at a port in the US.

The incident onboard the 4,900-ceu Hoegh Xiamen (built 2010) took place at Blount Island in Jacksonville, Florida.

Hoegh Autoliners confirmed that at about 1600 local time a fire broke out on the vessel's seventh deck shortly after it completed loading operations.

"There has been an explosion on the ship... firefighters are hurt," Jacksonville Fire and Rescue Department (JFRD) said via social media.

"Eight firefighters were transported to the hospital. Four of them were taken to Shands Gainesville burn unit..two by helicopter and two by ground transport... they are all stable, but with serious injuries."

"Our thoughts and prayers are with those firefighters and their families who were injured during this response," Hoegh Autoliners said.

The US Coast Guard said a 500-yard safety zone has been established around the Hoegh Xiamen.

The cause of the fire aboard the Norwegian-flagged vessel is said to be under investigation.

"All crew members are off the ship and accounted for... there are no injuries at this time," a spokesperson for the JFRD said.

Jacksonville Port Authority said other port operations have not been effected by the incident.

Captain Mark Vlaun, US Coast Guard Captain of the Port of Jacksonville, told local media at a briefing that the number one goal for crews throughout the night was to maintain the structural integrity of the ship.

“The effort really remains, one, of trying to protect the environment and to control and contain the fire as best we can to ensure that we don’t lose the structural integrity and risk having any pollution out in the water,” he said.

According to Vlaun, an oil spill response team was being brought in by Resolve Marine.

“They’ll be putting an oil boom around the vessel to contain the threat of any pollution,” he said.

“At this point, we do not have any pollution from or spill associated with this fire, but out of caution, we are going to begin booming the vessel, so that if there is any pollution at any point that we’ll be able to contain that spill.”

Hoegh Autoliners said it had activated its emergency response team and was working closely with all necessary authorities to contain the incident.

"Our priorities at this time are to secure the vessel and ensure the preservation of the local environment," it added.