MUSCAT/SANAA/DUBAI: U.S. Secretary of State John Kerry held talks Monday with officials in Oman on efforts to end Yemen’s 19-month-old conflict, state media in Muscat said.

Kerry and Oman’s Foreign Minister Yusuf bin Alawi discussed the “peaceful and humanitarian role played by the sultanate in Yemen,” ONA state news agency reported.

Kerry later met with Oman’s ruler Sultan Qaboos with whom he discussed “regional and international developments,” ONA said.

The visit to Oman is one of Kerry’s last trips as secretary of state before President Barack Obama’s administration steps down in January.

The U.S. chief diplomat has been pushing for a settlement in Yemen, where a deadly conflict between Iran-backed rebels and the government escalated after an Arab coalition intervened on behalf of the government in March 2015.

Oman, one of the few Arab states to have good relations with Iran, has used its links to mediate peace talks between the insurgents and the U.N.-recognized government of President Abed Rabbou Mansour Hadi.

It is also the only Arab nation in the Gulf that is not taking part in the coalition, although it maintains good relations with regional powerhouse Saudi Arabia.

More than 7,000 people have been killed and nearly 37,000 wounded in Yemen since March 2015, and the U.N. says millions are in need of food aid.

Another 21 million people urgently need health services, according to the U.N. health agency.

The World Health Organization Monday said Yemen is at risk of a significant cholera outbreak with the number of suspected cases doubling within 12 days to over 4,000.

The outbreak was declared by Yemen’s Health Ministry on Oct. 6. By Nov. 1 there were 2,070 suspected cases, rising to 4,119 by Sunday.

“The numbers of cholera cases in Yemen continue to increase, sparking concerns of a significant outbreak,” the WHO said in a report.

Cases confirmed as cholera by laboratory testing rose to 86 from 71 on Nov. 1. Eight people have died in the outbreak, as well as 56 from acute diarrhea.

Also Monday, at least 14 people were killed in central Yemen in airstrikes on fuel trucks by the Arab coalition, medics and witnesses said, with the coalition saying the vehicles were carrying rebel military supplies.

The medics and witnesses said at least 11 other people were wounded in the Monday morning attack in which two tanker trucks parked on a road linking the town of Yarim in Ibb province with the provincial capital, Ibb, were hit.

A medical source at Yarim hospital said the facility received the bodies of 10 people, including one soldier. The official said 15 wounded people were also brought to the hospital, some of them in serious condition.

The official later said that three other people had died.

Brig. Gen. Ahmad Asiri, spokesman for the coalition, said the convoy was en route from Ibb province carrying ammunition and other supplies for Houthi and allied forces near Taiz city.

The attack occurred at about 2 a.m., he said.

“There is a huge network of smuggling those weapons moving around. They try to camouflage. ... We were tracking them and when they stopped in the area of the 55th Brigade of the Republican Guard we attacked them in the night,” he said.

“It was so late at night that it was only the smugglers and the Houthi rebels around those vehicles,” he said.

Asiri added it was possible the trucks were carrying fuel in addition to ammunition and weapons.

Five other rebels, three soldiers and one civilian were killed Sunday in renewed violence in the southwestern province of Taiz, military sources said.

After Oman, Kerry will travel to Abu Dhabi for talks on regional conflicts, including Syria.