Britain is withdrawing some of its diplomatic staff from Iran while Norway has closed its mission in Tehran following Tuesday's mob assaults on British embassy compounds in the capital.

The British foreign office said Wednesday it ordered the partial evacuation because the safety of British embassy personnel and their families is an immediate priority. It did not say how many staff are leaving Iran or whether its Tehran mission will be closed. Western diplomats told the French news agency that the first British evacuees were taken to Tehran's airport Wednesday for a flight to Dubai.

The Norwegian government said it closed its Tehran embassy late Tuesday because of security concerns linked to the attacks on the British compounds. But, Oslo said the handful of Norwegian diplomats deployed to the Iranian capital will remain there for the time being.

British Prime Minister David Cameron said Tuesday Iran faces “serious consequences” for failing to defend the British compounds from Islamists who smashed embassy windows and ransacked offices as police looked on. The Islamists had gathered outside the buildings in a reflection of government anger at British sanctions imposed on Iran last week for pursuing an alleged nuclear weapons program.

The attacks drew more international criticism Wednesday. U.N. Secretary-General Ban Ki-moon's office said he expressed shock and outrage as he met with a British official on the sidelines of an aid conference in Busan, South Korea. The U.N. chief called on Iran to investigate the British embassy break-in and take measures to avoid any repetition there or at other diplomatic missions.

U.S. Secretary of State Hillary Clinton, also in Busan, strongly condemned the assaults as an “affront not only to the British people but also to the international community.” She said Washington expects Iran to protect the lives and properties of diplomats in accordance with international conventions.

China's foreign ministry said the embassy attacks were “contrary” to international law and norms and should be dealt with “appropriately.” It was a rare Chinese criticism of Iran, a key supplier of energy to the Chinese economy.

Iranian parliament speaker Ali Larijani said Wednesday Iranian police tried to maintain calm during the assaults. He also criticized Tuesday's statement by the U.N. Security Council condemning the incidents, calling it a hasty move designed to cover up “British and American crimes.”

Britain, the United States and Canada announced coordinated economic sanctions against Iran last week in response to Iran's pursuit of a nuclear program that U.N. experts say appears designed to build weapons. Iran says its nuclear program is peaceful.