FILE PHOTO: Britain's Prime Minister Boris Johnson reacts during a meeting with European Commission President Ursula von der Leyen (not pictured) inside 10 Downing Street in London, Britain January 8, 2020. Kirsty Wigglesworth/Pool via REUTERS

LONDON (Reuters) - British Prime Minister Boris Johnson said on Saturday that the accidental shooting down of a Ukrainian passenger jet in Iran reinforced the importance of de-escalating tensions in the Middle East.

“Iran’s admission that Ukraine International Airlines Flight 752 was shot down by mistake by its own armed forces is an important first step,” Johnson said in a statement.

Four British nationals were among the 176 people killed in Wednesday’s crash.

“We now need a comprehensive, transparent and independent international investigation and the repatriation of those who died. The UK will work closely with Canada, Ukraine and our other international partners affected by this accident to ensure this happens,” Johnson said.

“We can all see very clearly that further conflict will only lead to more loss and tragedy. It is vital that all leaders now pursue a diplomatic way forward.”

Iran said earlier that its military had mistakenly shot down the plane, saying air defences were fired in error while on alert in the tense aftermath of Iranian missile strikes on U.S. targets in Iraq. Iran had denied for days after the crash that it brought down the plane.