Three Yemeni civilians were wounded when four missiles fired by the Iran-backed Houthis landed in residential areas in Yemen’s central city of Marib as heavy fighting rages outside the strategic city, local officials and residents said on Sunday.

Large explosions rocked the city after the four missiles hit the airport, Al-Shareka and Rawdha neighborhoods, residents said.

Footage on social media showed thick smoke billowing from shelled areas as people fled.

Yemen’s Information Minister called on the UN and the US Yemen envoys to condemn the Houthi missile attacks and to designate the Houthi movement as a terrorist organization.

“The Houthi militia’s repeated targeting of the city of Marib, which is crowded with millions of residents and displaced people, with ballistic missiles is part of its attempts to inflict a big number of casualties among civilians. This is a cowardly act of revenge,” Moammar Al-Eryani said on Twitter.

The Houthi shelling of Marib came as the Arab coalition announced it had intercepted four explosive-rigged drones fired by the Houthis at southern areas in Saudi Arabia.

The coalition also said it had killed more than 115 Houthis in the past 24 hours after targeting their locations and military vehicles with 19 airstrikes in the provinces of Jouf and Marib, bringing the total number of Houthi deaths during the past 48 hours to more than 175.

At the same time, fierce fighting between government troops and the Houthis broke out on Sunday in flashpoint sites south of Marib city as the Houthis intensified their attacks, a local military official told Arab News.

The official said dozens of Houthis were killed in fighting in different locations in Juba district and seven others surrendered to government troops.

Yemeni military officials usually link the Houthi arbitrary shelling of the city of Marib to the death of rebel military leaders or defeats they have suffered.

“We think that a number of high-ranking Houthi military leaders were killed on Sunday in Marib province,” the official said.

The commander of the 143rd Infantry Brigade in Marib, Brig. Gen. Thayab Abdul Waded Al-Qibili, said on Sunday that army troops killed dozens of Houthis and destroyed 10 military vehicles during heavy fighting in Marib’s Rowdhat Jehim, praising the Arab coalition’s warplanes for targeting Houthi military reinforcements on the battlefields south of Marib, Yemen’s Defense Ministry news site reported.

Thousands of combatants and civilians have been killed in the province of Marib since February when the Houthis renewed a military offensive to seize control of the energy-rich city of Marib, the government’s last bastion in the north.