BEIJING (REUTERS) - China's Defence Ministry said on Tuesday that its warships had completed an evacuation of Chinese nationals from Yemen, with more than 570 people safely transported across the Red Sea to Djibouti to be flown home.

The Chinese were evacuated in two batches, one from Aden and the other, much larger group from Hodeidah, the ministry said in a statement on its website.

Eight foreign nationals were evacuated with them, it added, without providing details.

"Military officers must be the guardians of the people's security, and military ships must be like Noah's Ark for our compatriots," the ministry said.

With the mission now over, the Chinese ships will return to the Gulf of Aden to help in operations to fight Somali piracy, it added.

Violence has been spreading across Yemen since last year, when Iranian-backed Houthi fighters seized the capital, Sanaa, and effectively removed President Abd-Rabbu Mansour Hadi.

The Houthi militia, representing a Shi'ite minority that makes up around a third of Yemen's population, has emerged as the most powerful force in the Arabian Peninsula's poorest country.

Saudi Arabia has rallied Sunni Muslim Arab countries in an air campaign to support Hadi, who moved to Aden in February and is now in Riyadh after leaving Yemen in the past week.

China, a low-key diplomatic player in the Middle East despite its reliance on oil from the region, has expressed concern at the upsurge in violence in Yemen and called for a political solution.