A battalion of Sudanese troops arrived in Yemen's southern port city of Aden, bolstering Saudi-led Arab forces trying to keep out the Iran-backed Houthis and curb the growing presence of Islamist militants.

Aden, a strategic port and shipping hub, became the seat of the Yemeni government earlier this year after the Houthis, a clan from northern Yemen, seized the capital Sanaa and forced President Abd-Rabbu Mansour Hadi to flee to the south.

A military source in Aden said that 300 Sudanese soldiers and officers arrived by sea at the weekend. Their purpose was to "help maintain security for the city against the Houthis and Saleh," the source said, referring to former President Ali Abdullah Saleh, whose supporters have sided with the Houthis.

Hadi escaped to Saudi Arabia as the Houthis, who follow the Zaydi branch of Shi'ite Islam, advanced towards Aden in March. Prime Minister Khaled Bahah returned from exile after anti-Houthi fighters, backed by the Arab coalition, drove the Houthis and their allies out of the city in July.

However, they have not managed to restore security there. Islamist militant suicide bombers killed 15 people in attacks on the Yemeni government's headquarters and Arab coalition outposts in Aden earlier this month.

"Our troops in Yemen are ready to do their military task under the command of the alliance military leadership," Sudanese army spokesman Brigadier General Ahmed Khalifa Alshami said. "Sudan is committed to restore legitimacy in Yemen."