A Chinese naval frigate has evacuated 225 foreign citizens from strife-torn Yemen, its foreign ministry said, marking the first time that China's military has helped other countries evacuate their people during an international crisis.

Ten different nationalities were among the evacuees picked up on Thursday afternoon from Aden, Yemen's second city, and transported to Djibouti, the Ministry of Foreign Affairs said in a statement on its website late Thursday.

The ministry said the countries - Pakistan, Ethiopia, Singapore, Italy, Germany, Poland, Ireland, Britain, Canada and Yemen - requested China's help with the evacuation.

A diplomatic source familiar with the operation said it was "very risky" and that fighting had come close to the Chinese warship.

"The Chinese ship was in the right place at the right time," the source said.

YEMEN-SECURITY/CHINA

A Chinese solider of People's Liberation Army (PLA) checks the body condition of a non-Chinese citizen before an evacuation from Aden. (Stringer/Reuters)

Violence has been spreading across Yemen since last year, when Iran-backed Shia Houthi fighters seized the capital, Sanaa, and effectively removed President Abd-Rabbu Mansour Hadi. A Saudi-led coalition has hit the rebels with air strikes over the past week.

A state television report on Friday showed evacuees, who were mostly Pakistani, arriving in Djibouti.

"We are really thankful to the Chinese government, who really helped us, and took us out [with] the school children," one woman told China Central Television.

The broadcaster showed footage young children stepping off a Chinese warship waving Chinese flags, and in one case, kissing a seaman on the cheek.

The evacuation of foreigners bolsters China's image at home and abroad, according to Shen Dingli, an international relations professor at Fudan University in Shanghai.

"We wouldn't look very good if we have the capacity to help others but no heart to do it," Shen said.

"Now we look really good," he added.

China had earlier evacuated 571 of its own nationals, along with eight foreigners who worked for Chinese companies.

Once-reclusive China has become increasingly active in disaster relief and humanitarian aid abroad as its global economic interests widen.

"China has been keen to learn from the experience of other countries on how to evacuate people, especially after Libya," said one senior Western diplomat in Beijing. "It's good to see China taking more of an interest in this."

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

Beijing drew international praise last year when it sent elite troops to help Ebola-hit Liberia by building a treatment centre and help transport medical supplies.

China also sent a state-of-the-art hospital ship to the Philippines in 2013 after one of the world's biggest typhoons killed thousands.