ADEN, Yemen, May 15 (Xinhua) -- Battles raging between the Yemeni government forces and the Houthis continued in the country's southern province of al-Dhalea, leaving five soldiers and seven rebels killed on Wednesday, a military official told Xinhua.

The pro-government forces continued in confronting the Houthi rebels who insist on advancing toward al-Dhalea province, leaving five soldiers killed following hours of fighting in the area, said the local military official, who asked to remain anonymous.

Houthis desperately tried to advance further to seize government-controlled sites in Qataba district to the northwestern part of al-Dhalea, but faced fierce resistance from the army soldiers, the source said.

"The army forces air-covered by airstrikes from the Saudi-led coalition lost five soldiers in the ongoing battle with the Houthi rebels in area," he said.

He added that Houthis carried out artillery shelling against the government forces after losing around seven of their rebel fighters in the same battles.

According to information gathered from military sources earlier in the day, scores of pro-government soldiers backed by pick-ups equipped with heavy machine guns arrived in Qataba and began confronting Houthis.

On Tuesday, UN Special Envoy to Yemen Martin Griffiths tweeted that he is deeply concerned about the ongoing escalation of conflict in Dhale, and urged all parties to exercise utmost restraint.

The UN envoy said that any military escalation risks a setback in the progress towards peace in Yemen.

Both warring sides continued to mobilize large numbers of fighters to the frontlines in al-Dhalea amid non-stop armed confrontations taking place since weeks ago in the southern region.

Last month, scores of Houthi fighters launched a series of intense armed attacks on the positions of government forces and succeeded in seizing the district of Al Husha in the west of al-Dhalea.

The areas in the north and west of the government-controlled al-Dhalea have been witnessing continuous fighting between government forces and Houthi fighters for four years.

Yemen has been plagued by a civil war since late 2014 after Houthi rebels revolted and forced the internationally-recognized government of President Abd-Rabbu Mansour Hadi into exile.