Local sources told Al-Jazeera that dozens of people were killed and wounded as a result of battles that erupted in the central province of Ma'rib, between the Yemeni army and tribesmen on the one hand and the Houthi fighters on the other, while the United Nations warned Wednesday of the "devastating repercussions" of the violent fighting on civilians in Yemen.

The sources added that the Yemeni army, with the support of tribesmen, launched a counterattack on the Houthis, who had taken control of areas south of the "Al-Juba" district in Marib.

The sources accused the Houthis of firing two ballistic missiles at areas in the Juba district, one of which targeted a fuel station, causing casualties, including civilians, and the burning of several cars.

In turn, the Yemeni army said that its forces repelled Houthi attacks on several fronts in Marib.

Meanwhile, the Saudi-Emirati coalition confirmed that it had carried out 19 operations targeting the equipment and fighters of the Houthi group in Abdiya, Marib, during the past 24 hours.

The coalition had announced the destruction of two booby-trapped boats belonging to the Houthis and thwarting the implementation of two imminent attacks.

The coalition accused the Houthis of continuing to threaten shipping lanes and global trade in the Bab al-Mandab strait and the southern Red Sea.

On the other hand, Houthi media outlets said that "coalition warplanes launched 33 raids on sites in the Marib and Al-Jawf governorates."


UN warning

In a related context, the United Nations warned, on Wednesday, of the "devastating repercussions" of the violent fighting on civilians in the governorates of Marib, Al-Bayda (central) and Shabwa (southeast) in Yemen.

"Intense fighting continues in Yemen, including in the governorates of Ma'rib, Shabwa and Al Bayda, where clashes have escalated in recent weeks," said Stephane Dujarric, spokesman for the United Nations Secretary-General.

Dujarric added, in statements to reporters at the organization's headquarters, that this escalation has increasingly devastating repercussions on civilians, as about 10,000 people were displaced in Marib last September, and this is the highest rate recorded in the governorate in one month since the beginning of the year.

"The United Nations is particularly concerned about the situation in the Abdiya district, southwest of Marib, where approximately 35,000 people live, including many who have sought refuge after fleeing the conflict in neighboring areas," he added.

Dujarric urged all parties to the conflict to fulfill their obligations under international humanitarian law, including ensuring the protection of civilians and providing a safe passage to flee from conflict areas.

It also called for facilitating safe, timely and sustainable humanitarian access to all affected areas in Yemen.

For about 3 weeks, the Houthis have besieged the Abdiya district from all ports, after government forces, with the support of the Arab coalition, repelled all their attacks aimed at controlling it.

Marib is the last stronghold of the legitimate authorities in northern Yemen, and the Houthis have been carrying out a massive military campaign for nearly a year with the aim of controlling it.


Diplomatic moves

On the diplomatic front, the US envoy to Yemen, Timothy Lenderking, is expected to arrive on Wednesday evening in the Omani capital, Muscat, as part of a tour that includes Jordan, Saudi Arabia and the UAE.

Al-Jazeera correspondent quoted sources as saying that Linderking will meet with high-ranking Omani officials and the head of the Houthi delegation, Muhammad Abdul Salam, who is residing in the Sultanate.

In turn, the US Bloomberg Agency reported on Wednesday that Iran had asked Saudi Arabia to reopen consulates and restore diplomatic relations as a prelude to ending the war in Yemen.

The agency quoted two people familiar with the course of the talks between the two countries that the timing of opening consulates and restoring relations is the main point in the talks mediated by Iraq between the two countries.

The agency said that while world powers are pushing for reviving the nuclear agreement, the Iranian Republic has held four rounds of talks with the aim of easing tension with Saudi Arabia.

The focus of the talks was on Yemen, where every country supports the warring parties.

Yemen has been witnessing a war for nearly 7 years, which has killed more than 233,000 people, and 80% of the population, numbering about 30 million, has become dependent on support and aid, in the worst humanitarian crisis in the world, according to the United Nations.

The conflict has had regional spillovers, since March 2015, as a coalition led by the neighboring Saudi Arabia has been carrying out military operations in support of the government forces, in the face of the Iranian-backed Houthis, who control several governorates, including the capital, Sanaa.