Yemen's exiled President has today returned to rally forces loyal to him as more than 50 people were killed in the latest clash of the country's civil war.

President Abd-Rabbu Mansour Hadi arrived in the southern port city of Aden in a bid to recapture the city of Taiz, according to a presidency official.

His arrival came as his supporters made advances amid heavy fighting in the south-western province surrounding Taiz which killed around 45 fighters from both sides on Monday, medical sources said. The violence is the latest in the four-year civil war which began as part of the Arab Spring in 2011.

"Twenty-five pro-Hadi fighters were killed in an ambush laid for them by Houthi and Saleh forces at the Bab al-Mandeb, and 20 Houthi fighters were killed in fighting and coalition air strikes," a medic from Taiz told Reuters, adding that a family of eight were killed in an air strike on the city.

At least 5,700 Yemenis have been killed during seven months in a civil war that has pitted supporters of the exiled government, backed by a Saudi-led Arab coalition, against Houthi militia and forces loyal to former president Ali Abdullah Saleh who are allied to Iran. As Christian Today reported, despite Saudi Arabia's horrendous human rights record and links to terrorist organisations, it is Britain's largest trading partner in the Middle East.

The exiled government have all the military strength of Saudi Arabia behind them and the conflict has turned into "among the worst humanitarian crises in the world," according to Oxfam.

It was not immediately clear how long Hadi would stay in the country or whether his visit would herald the permanent return of his exiled administration from the Saudi capital Riyadh.

Mukhtar al-Rahbi, an official in Yemen's presidency, said Hadi had arrived in Aden to oversee the campaign to retake Taiz, which has been battered by fighting. Medics in the city say more than 1,600 people have died there.

"He will also meet with military officials to assess the security situation and to oversee the merging of the resistance forces into the army and security forces," al-Rahbi said.

The coalition has made some progress on the battlefield and took control of Aden in July, but the Houthis still retain control of much of Yemen, despite almost daily air bombardment from Arab warplanes.

Additional reporting by Reuters.