China expressed concern Thursday over the situation in Iran after an attack by protesters led Britain to close its Tehran embassy and several European countries recalled ambassadors for consultations.

The mission was attacked on Tuesday by protesters angry over new British sanctions against Iran's financial system that followed a recent UN report containing evidence that Iran is pursuing nuclear weapons.

"China has noted the tough reactions made by the relevant countries over this event and is concerned over the development of the situation," Chinese foreign ministry spokesman Hong Lei told reporters.

"We hope relevant countries will keep calm and exercise restraint and avoid taking emotional actions that may rachet up the confrontation."

China and Russia -- key allies of Iran -- have often sought to take a softer stance on the Islamic republic than their fellow members of the UN Security Council.

China and Iran have become major economic partners in recent years, thanks partly to the withdrawal of Western companies in line with sanctions against Tehran.