ADEN, Yemen/CAIRO: Clashes in Yemen killed at least 66 people in 24 hours, medics and security sources said Sunday, as pro-government forces pushed to oust rebels from a key stretch of coastline. Airstrikes by an Arab-led coalition and fighting near the strategic Bab al-Mandab strait killed at least 52 fighters among Houthi rebels and allied troops loyal to ex-president Ali Abdullah Saleh, the sources said.

Fourteen members of the pro-government forces were also killed.

Forces loyal to President Abed Rabbou Mansour Hadi launched a vast offensive on Jan. 7 to retake the Dhubab district overlooking the Bab al-Mandab, a key maritime route connecting the Red Sea and the Indian Ocean.

Coalition warplanes and Apache attack helicopters have been pounding rebels in support of pro-Hadi forces advancing toward the Red Sea city of Mokha, military sources said.

By Sunday, loyalist forces were within 10 kilometers of Mokha, they said, but the offensive has been slowed by mines laid by rebels.

The rebels took their dead to a military hospital in Hudaida, a major western port city they control, a medical source told AFP.

The hospital received 14 dead Saturday and 38 Sunday, as well as 55 wounded rebels, the source said.

On the pro-government side, 14 soldiers were killed and 22 wounded, according to medics in the southern port city of Aden where Hadi’s government is based.

The coalition intervened in Yemen in March 2015 in support of the beleaguered president.

But despite its massively superior firepower, the rebels and their allies still control the capital Sanaa and much of the central and northern highlands, as well as the 450-kilometer Red Sea coast.

Sunday, Egypt extended its military participation in the coalition operation in Yemen. The presidency’s statement did not specify how long the extension would be for.

“The National Defense Council agreed during the meeting to extend the participation of the required elements from the Egyptian armed forces in a combat operation outside the nation’s border to defend Egyptian and Arab national security in the Gulf, Red Sea and Bab al-Mandab areas,” the statement said.

Meanwhile, United Nations peace envoy Ismail Ould Cheikh Ahmed arrived in Sanaa Sunday for talks and to push a peace plan that would restore a cease-fire and lead to a political transition in the country.

The plan would lead to a political transition under which Hadi’s powers would be significantly reduced.

The World Health Organization says that more than 7,400 people have been killed since the coalition intervention began.

A U.N. spokesman has said the civilian death toll alone could top 10,000.