The source, who preferred to be unnamed, said that the Houthi fighters launched an intensified shelling against government-controlled sites and residential areas in Tuhyata district of Hodeidah province.

He said that around 45 mortar shells were fired randomly by the Houthi rebels against Tuhyata, leaving three civilians killed and nearly 10 others critically injured.

A medical official confirmed to Xinhua that "the field hospitals couldn't cope with the increased number of injured civilians as a result of the indiscriminate Houthi shelling."

"Some seriously injured people including civilians were shifted to receive treatment at hospitals in Aden province," the source said.

A statement revealed by the pro-government Giants Brigades blamed the Iranian-backed Houthi rebels for "committing a new massacre in Hodeidah."

A source of the pro-government forces told Xinhua by phone saying that "Houthis started attacking our military locations and there will be a response for that violation."

"Today, the Houthi rebels stepped military operations with no respect for the cease-fire brokered by the United Nations in Hodeidah," the source added.

The UN Special Envoy to Yemen Martin Griffiths concluded Thursday his two-day talks with senior leaders of the Houthi group but did not succeed in convincing the group to start withdrawal from Hodeidah.

The warring forces have so far failed to withdraw from Hodeidah and its southern districts in accordance with the UN-sponsored Stockholm Peace Agreement reached last December.

The deal aimed to avert an all-out offensive on the lifeline port city, which is the key entry of Yemen's most commercial imports and international aid.

The Saudi-led military coalition 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 and Hodeidah. 

Image: File picture from UN website