The tanker, which can carry tens of thousands of tonnes of jet fuel, was anchored when the smaller container ship struck it early on Monday (9pm AEDT), rupturing its cargo tank and releasing fuel into the sea, its operator said. Its owner Stena Bulk gave the same details.
Two maritime security sources said there was no indication of any malicious activity or other actors involved in the incident.
Britain's coastguard said in a statement that 36 crew members were taken safely ashore, with one person hospitalised.
The coastguard said one crew member of the Portuguese-flagged cargo ship Solong remained missing and the search had ended.
But there was still a risk of environmental damage, experts said.
The tanker, the Stena Immaculate, operated by US logistics group Crowley, was carrying Jet-A1 fuel when it was struck by cargo ship Solong while anchored near Hull, Crowley wrote on X.
The tanker is part of a US government program designed to supply the armed forces with fuel when required.
A US military spokesperson told Reuters on Monday it had been on a short-term charter to the US Navy's Military Sealift Command.
The Solong's Hamburg-based owner Ernst Russ said separately that the vessel had been involved in a collision with the Stena Immaculate in an incident while the vessel was transiting the North Sea, off the British coast of Humberside.
"Both vessels have sustained significant damage in the impact of the collision and the subsequent fire," Ernst Russ said in a statement.
"13 of the 14 Solong crew members have been brought safely shore. Efforts to locate the missing crew member are ongoing."
The Solong is carrying 15 containers of sodium cyanide, a toxic chemical used mainly in gold mining, and an unknown quantity of alcohol, according to a casualty report from maritime data provider Lloyd's List Intelligence.
Emergency teams sent a helicopter, fixed-wing aircraft, lifeboats and nearby vessels with firefighting capability to the incident.
"A fire occurred as a result of the allision and fuel was reported released," Crowley said. An allision is a collision where one vessel is stationary.
Crowley said there had been multiple explosions on board.
Martin Slater, director of operations at Yorkshire Wildlife Trust, said East Yorkshire's coast was home to protected and significant colonies of seabirds including puffins and gannets, with many offshore on the sea ahead of the nesting season.
A Greenpeace spokesperson said any impact would depend on factors including the amount and type of oil carried by the tanker, the fuel carried by both ships, and how much of that, if any, had entered the water, plus the weather conditions.
One insurance specialist said the pollution risk was lower than if the tanker had been carrying crude oil.
"A lot depends really on cargo carried, how many tanks were breached and how bad the fire is," the insurance source said.
The coastguard said British government officials were working with salvage and insurance companies, adding that both vessels remained on fire with aircraft monitoring the situation.
Mark Sephton, professor of Organic Geochemistry at Imperial College London, added that the relatively small hydrocarbons of jet fuel could be degraded by bacteria more quickly than larger molecules.
"The fact that we are moving into warmer temperatures will also speed up biodegradation rates," he said.
The incident occurred in a busy waterway, with traffic running from the ports along Britain's northeast coast to the Netherlands and Germany.
with PA and AP
