ADEN, Yemen, May 20 (Xinhua) -- At least four people were killed Monday when a civilian vehicle was bombarded while traveling in Yemen's northwestern province of Hajjah, a military official told Xinhua.

The civilian vehicle was bombarded as it was passing through a side road in Mastaba district located in the northern part of Hajjah province, leaving four people killed, said the official, who asked to remain anonymous.

He said that the area in which the civilian vehicle was bombed has been witnessing armed confrontations between the Yemeni government forces and the Houthi rebels.

The Iranian-backed Houthi group blamed the Saudi-led coalition for targeting the civilian vehicle with an airstrike.

The Houthi-affiliated Masirah television network reported that "preliminary reports indicate that four civilians were killed when a Saudi-led airstrike targeted a citizen's vehicle while it was heading to a market in Mastaba district."

On Saturday, Yemen's Defence Ministry website reported that pro-government forces succeeded in liberating several areas from the Houthis' control in Hajjah.

Warplanes launched a series of airstrikes to support the on-ground government forces while attacking the Houthi-controlled sites, according to the ministry's website.

Saudi Arabia intervened in Yemen in March 2015 to support the government of President Abd-Rabbu Mansour Hadi after Houthi rebels forced him into exile and seized much of the country's north, including the capital Sanaa.

Entering its fifth year, the war has killed tens of thousands of people, displaced 3 million others and pushed over 20 million Yemenis into the brink of famine.