ADEN, Yemen, Sept. 9 (Xinhua) -- At least six Yemeni citizens were killed and several others injured on Monday when an explosion rocked a weapons store in the Houthi-controlled Red Sea port city of Hodeidah, a military official told Xinhua.

The pro-government military source said on condition of anonymity that "a huge explosion rocked an abandoned plastic factory used by Houthis to store weapons in Zafran area in downtown Hodeidah."

Several houses located nearby were badly affected by the weapons store explosion that occurred in a densely populated area in Hodeidah, said the source.

He added "an unknown number of casualties were caused among the Houthi fighters who were present around the blast site."

The Houthis-affiliated Masirah television network reported that pro-government forces launched an artillery shelling against the Zafran neighborhood in Hodeidah.

It said that around ten people were injured, but mentioned no details about the weapons store explosion.

A government source accused the Houthi group of storing weapons in densely populated areas of Hodeidah in addition to establishing factories for manufacturing explosives there.

Hodeidah is the main Yemeni port city on the Red Sea and key entry of most Yemen's commercial imports and humanitarian aid.

The grinding war has lasted more than four years, pushing more than 20 million people to the verge of starvation.

Iran-allied Houthis control much of Hodeidah while the Saudi-backed government troops have advanced to the southeastern districts.