A Twickenham man was among three Britons killed in the Ukraine passenger plane crash..

Reservoir engineer Mr Zokaei, 42, from Twickenham, was on holiday from working at BP's site at Sunbury, the oil firm said.

Mr Zokaei worked at the company for more than 14 years, moving through a number of roles, according to his LinkedIn profile.

He graduated from Heriot-Watt University in Edinburgh in 2004 with a masters in petroleum engineering, it added.

BP said in a statement: "With the deepest regret, we can confirm that one of our colleagues at BP, Sam Zokaei, was a passenger on the Ukrainian International Airlines plane that crashed in Iran this morning, reportedly with no survivors.

"We are shocked and deeply saddened by this tragic loss of our friend and colleague, and all of our thoughts are with his family and friends."

The Iranian military has disputed suggestions the airliner was brought down by a missile, something Downing Street added there was "no indication" of, after the Ukrainian authorities refused to rule out the prospect.

Officials in Iran blamed an engine fire, while the Ukrainian president ordered a criminal investigation into the crash.

Announcing that a team of security officials and experts will fly to Iran to aid the investigation, Volodymyr Zelenskyy added: "Our priority is to establish the truth and those responsible for this terrible catastrophe."

The airline ruled out human error, and crew were not said to have made an emergency call.

The airline said: "According to our records, the aircraft ascended as high as 2,400 metres.

"Given the crew's experience, error probability is minimal. We do not even consider such a chance."

Ukrainian Foreign Minister Vadym Prystaiko confirmed the death toll also involved 82 Iranians, 63 Canadians, 11 people from the Ukraine, nine of whom were crew members, 10 Swedes, four Afghans and three Germans.

He said: "An investigation commission should be set up of representatives of the civil and aviation agencies responsible for civil aviation. We have to work out all the possible versions.

"Regardless of the conclusions regarding the causes of the Iranian catastrophe, the airworthiness of the entire civilian fleet will be tested.

"I keep all measures on personal control. I very much ask everyone to refrain from speculation and putting forward untested versions of the disaster before the official announcements."