The number of suspected cases reaches almost 30,000 in the war-torn country whose healthcare system is collapsing.
US forces have killed seven suspected members of al-Qaeda in the Arabian Peninsula (AQAP) during a ground raid in Yemen, the Pentagon has said.
The operation in the early hours of Tuesday came some four months after a botched US commando raid against the group that left more than a dozen civilians dead.
US forces used “a combination of small arms fire and precision airstrikes” to attack a compound in the Marib governorate, with the support of Yemen’s authorities, a statement by the US Central Command said on Tuesday.
“Raids such as this provide insight into AQAP’s disposition, capabilities and intentions, which will allow us to continue to pursue, disrupt, and degrade AQAP.”
Two US officials, speaking to the Reuters news agency on condition of anonymity, said the primary objective of the raid was to gather intelligence. There were no known US casualties or injuries, they said.
The statements could not be independently verified.
The US has increased attacks against AQAP, which it regards as the most dangerous branch of the armed group, since President Donald Trump took office in January.
That has included an ill-fated raid against AQAP in January that left at least 16 civilians, including women and children, dead. AQAP fighters and a US Navy SEAL were also killed in the operation.
Yemen has been torn apart by conflict since 2014, when Houthi fighters allied with troops loyal to former president Ali Abdullah Saleh captured large expanses of the impoverished Arabian Peninsula country, including the capital Sanaa.
AQAP and a local affiliate of the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) group have exploited Yemen’s war to carry out assassinations and bombings, mostly in lawless areas in the south.
According to the UN, more than 10,000 people have died – nearly half of them civilians – since an Arab coalition began a campaign of air strikes in March 2015 to drive out the Houthis and their allies.