ADEN, Yemen, May 3 (Xinhua) -- Pro-government Yemeni forces backed by the Saudi-led Arab coalition launched on Friday attacks against Houthi-controlled sites in al-Dhalea province in south Yemen, a military official told Xinhua.

"The armed forces fought fierce battles and succeeded in regaining control over the strategic Ellal camp and the main headquarters of the special forces in Qataba district in al-Dhalea province," the official said on condition of anonymity.

The Houthis were forced to withdraw from key military sites they seized previously as the pro-government forces received large reinforcements and began launching offensives, the official said.

He added that Yemen's government pushed two elite battalions backed by tanks and armored vehicles to battle the Houthis in the northern parts of al-Dhalea.

Local residents confirmed to Xinhua that several Houthi-controlled sites came under heavy airstrikes from the Saudi-led coalition before the government forces ground attacks.

Intense battles between the Houthi fighters and pro-government forces are still ongoing in northern areas of al-Dhalea province, leaving casualties on both sides, according to local officials.

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 province of 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.