A major rescue operation was being coordinated by the UK Coastguard as images showed a huge plume of thick, black smoke and flames rising from the scene about 10 miles (16 kilometres) off the coast.

The Stena Immaculate was "anchored off the North Sea coast near Hull ... (and) was struck by the container ship Solong," the Stena's US-based operators Crowley said in a statement.

The impact of the collision "ruptured" the cargo tank "containing A1-jet fuel" triggering a fire, with fuel "reported released".

The 32 injured had been brought ashore for treatment in three vessels, the Grimsby port director Martyn Boyers told AFP, adding "ambulances were queueing on the quay" in the northeastern English fishing port.

All of the crew on board the tanker owned by Swedish shipowner Stena Bulk were confirmed to be alive, Lena Alvling, a spokesperson for the firm told AFP.

There were reports of "fires on both ships" that UK lifeboat services were responding to, the Royal National Lifeboat Institution (RNLI) confirmed to AFP.

A spokesman said the Coastguard was carrying out an assessment of the likely counter pollution response required, while a government body probing marine accidents deployed a team to Grimsby.

"Our team of inspectors and support staff are gathering evidence and undertaking a preliminary assessment of the accident to determine our next steps," a Marine Accident Investigation Branch spokesperson said.

According to environmental campaign group Greenpeace, it was "too early to assess the extent of any environmental damage".

"In the case of an oil spill or any loss of hazardous cargo from the container ship involved, the speed of the response will also be crucial in limiting any impact," a Greenpeace spokesperson said.

- Humber traffic suspended -

All vessel movements were "suspended" in the Humber estuary which flows into the North Sea, according to the Associated British Ports (ABP).

The ABP, which operates in the Ports of Hull and Immingham in the region, added it was "assisting" the Coastguard.

The International Maritime Organization told AFP "the current focus is on the firefighting and search and rescue operation".

UK Transport Secretary Heidi Alexander said she was "concerned to hear" about the collision and thanked all the emergency services which rushed to the scene.

The alarm about the crash near the port city of Hull in East Yorkshire was raised at 0948 GMT.

A Coastguard helicopter, a plane, lifeboats from four towns and other nearby vessels were part of the large rescue operation, the Coastguard said.

The cargo ship was the Portuguese-flagged "Solong", owned by the German company Reederei Koepping.

The 140-metre-long (460 foot) cargo vessel, left Grangemouth in Scotland and was bound for Rotterdam, according to website Vessel Finder.

- Collisions rare -

Vessels with firefighting capabilities have been dispatched to the scene off the northeast coast.

Collisions remain rare in the busy North Sea.

In October 2023, two cargo ships, the Verity and the Polesie, collided near Germany's Heligoland islands in the North Sea.

Three people were killed and two others are still missing, considered dead.

The Isle-of-Man-flagged Verity, which was carrying steel from the northern German port of Bremen to Immingham, sank.

In October 2015, the Flinterstar freighter -- carrying 125 tonnes of diesel and 427 tonnes of fuel oil -- sank after colliding with the Al Oraiq tanker eight kilometres (five miles) off the Belgian coast on October 6, 2015.

A major North Sea oil spill took place in January 1993 when the Liberian tanker Braer suffered engine damage while en route from Norway to Canada.

Water seeped into the holds of the ship, which ran aground off Scotland's Shetland Islands and released 84,500 tonnes of crude oil.