BEIJING (REUTERS) - A Chinese envoy who visited Saudi Arabia and Iran over the past week has called for both countries to exercise calm and restraint amid an ongoing feud between the two countries, in a rare diplomatic foray into the region by Beijing.

Tensions between the Sunni Muslim kingdom of Saudi Arabia and Shi'ite Muslim Iran have escalated since the Saudi authorities executed Shi'ite cleric Nimr al-Nimr on Jan 2, triggering outrage among Shi'ites across the Middle East.

In response, Iranian protesters stormed the Saudi Embassy in Teheran and its consulate in Mashhad, prompting Riyadh to sever relations. Teheran then cut all commercial ties with Riyadh, and banned pilgrims from travelling to Mecca.

Other Arab countries have recalled envoys to Iran and the United Arab Emirates downgraded relations in solidarity with Saudi Arabia.

In separate statements on its website on Monday, China's Foreign Ministry said Vice-Foreign Minister Zhang Ming met senior Saudi and Iranian officials on his trip.

While in Saudi Arabia, Mr Zhang talked about the situation between Saudi Arabia and Iran and "hopes the relevant parties maintain calm and exercise restraint, step up dialogue and consultations and jointly promote an amelioration of the situation", the ministry said.

In Iran, Mr Zhang repeated the message about calm and restraint, adding that China hopes for the maintenance of peace and stability in the region.

Both countries expressed their appreciation for China's role in the region, the statements added.

While relying on the region for oil supplies, China has tended to leave Middle Eastern diplomacy to the other five permanent members of the UN Security Council - the United States, Britain, France and Russia.

But China has been trying to get more diplomatically involved, especially in Syria, recently hosting both its foreign minister and opposition officials.