Oil tanker and cargo ship crash in North Sea

The UK Coastguard said it had ended the search for a missing crew member from a container ship that crashed into an oil tanker in the North Sea on Monday.

The tanker caught fire after the crash, raising fears that a chemical spill could harm marine life.

The stricken vessels sit about 10km off the coast of East Yorkshire, England, with 32 casualties taken ashore. Greenpeace warned about the tanker's jet fuel cargo entering the water close to a breeding ground for harbour porpoises. Also toxic to fish and other sea creatures was 15 containers holding sodium cyanide on one of the ships.

The US-flagged MV Stena Immaculate was at anchor when it was hit by the Solong, a Portuguese container ship sailing from Grangemouth to Rotterdam.

The Stena Immaculate was carrying jet fuel and spilt some of its cargo after a tank was ruptured, the ship's managing company Crowley said. The crew abandoned ship after several explosions but were all accounted for.

The UK Coastguard said it was carrying out an assessment for a potential counter-pollution response. The Stena Immaculate was carrying about 130,000 barrels of fuel, analytics firm Vortexa estimates.

There were reports of "fires on both ships" that UK lifeboat services were responding to, said the Royal National Lifeboat Institution. "A number of people had abandoned the vessels," the RNLI added. TV images showed a plume of thick, black smoke and flames rising from the scene 16km off the coast.

US shipping expert Sal Mercogliano suggested the Solong was on autopilot on its run down England’s east coast before the crash.

Martyn Boyers, chief executive of the Port of Grimsby East, said 13 casualties were brought in on a Windcat 33 vessel, followed by another 19 on a harbour pilot boat. He said "ambulances were queuing on the quay" to take the injured to hospital.

Mr Boyers said he was told of "a massive fireball" and added: "It's too far out for us to see – about 10 miles [16km] – but we have seen the vessels bringing them in."

The International Maritime Organisation confirmed on Monday that "the current focus is on the firefighting and search and rescue operation".

The Marine Accident Investigation Branch says it sent 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," it added.

Swedish tanker company Stena Bulk confirmed it owns the oil tanker involved and added that it was operated by Crowley, a maritime company based in the US.

The Stena Immaculate is one of only 10 tankers held by the US Department of Transport’s Tanker Security Programme, designed to bring fuel to the US Army during armed conflict or national emergencies, said retired Royal Navy warship commander Tom Sharpe.

The most likely cause was human error, as the Solong "T-boned" the tanker midships while travelling at 16 knots, considered medium-high speed, likely on autopilot”, Mr Sharpe told The National.

“If you're keeping any sort of look out, then somebody, at some point, does something right," he said. "Once the risk of collision has become inevitable, a ship will manoeuvre or slow down to minimise the damage or make it a glancing blow to lessen that collision.”

He added that if the ships continued to burn furiously, they would both “almost certainly” sink and it was “just a question of time now”.