ADEN - A battalion of Sudanese troops arrived in Yemen's southern port city of Aden on Saturday, military officials said, 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 which follows the Zaydi branch of Shiaism, 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 on Saturday. 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 advanced towards Aden in March and has since been back only for a brief visit. But Prime Minister Khaled Bahah returned 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 on Oct. 6.

"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."

The Arab coalition says its aim is to restore Hadi's government to power in Yemen. At least 5,400 people have died since it began an air offensive in March.

The Arab coalition spokesman, Brigadier General Ahmed al-Assiri confirmed the arrival of the Sudanese troops to Arab television channels.

They will join contingents from the United Arab Emirates, Saudi Arabia and Bahrain on the ground.

In Aden, residents report that armed men, including Islamist militants associated with al Qaeda, roam the streets. Unidentified gunmen killed a UAE national in Aden on Saturday at a shop, according to a local security source. The UAE state news agency WAM reported that a coalition soldier had died but gave no further details.

Meanwhile, Yemen's government will attend UN-sponsored talks with the Houthis and their allies, a government spokesperson said on Sunday, in a fresh bid to end months of fighting that has killed more than 5,000 people.

The Saudi-backed government said on Saturday it had been studying an invitation from the United Nations to attend a new round of talks in an undisclosed location.

"The decision has been taken to attend (the talks) and a letter will be sent to the UN secretary-general (about that)," Rajeh Badi, the government spokesman, told Reuters.

UN special envoy to Yemen Ismail Ould Cheikh Ahmed has been in Saudi Arabia for discussions with Yemeni President Abd-Rabbu Mansour Hadi and other senior Yemeni officials over the talks.

A previous round of UN-sponsored talks in Geneva between the Yemeni government and the Houthis in June failed to achieve a breakthrough.

At least 5,400 people have been killed in the fighting in the poorest country on the Arabian Peninsula, and the United Nations says the humanitarian situation, exacerbated by a Saudi blockade of Yemen's ports, is "critical".

Saudi Arabia has been leading an Arab military intervention since March to try to restore Hadi's government, now based in Aden, and fend off what it sees as creeping Iranian influence.