A UN food agency staff member has been killed in an attack in Taiz province in southern Yemen, the health minister of the internationally recognized government said Friday.

Health Minister Qasem Buhaibeh tweeted his condolences to the staffer’s family, calling for security forces to “arrest the criminals” responsible for the killing.

He had previously identified the staffer before later removing his name and nationality.

Fighting between an Arab-led coalition backing Yemen’s internationally recognized government and the Houthis has eased over the past year, although sporadic attacks continue.

In April, a Saudi delegation led by Mohammed al-Jaber, the Kingdom’s ambassador to Yemen, traveled to Sanaa for direct talks with the Houthis, fueling hopes for a negotiated settlement.

The war has displaced 4.5 million Yemenis internally and pushed more than two-thirds of the population into poverty.

The UN’s World Food Program said it was ‘deeply saddened’ by the killing of a staff member in Yemen’s Taez province.

“WFP is deeply saddened that a dedicated staff member was killed in Yemen today by unknown gunmen,” a spokesperson for the UN agency told AFP, declining further comment.