U.S. Central Command continued strikes against the group Sunday and Monday, launching a campaign that may last weeks, officials said.

The U.S. military’s surprise strikes on Yemen’s Houthi militants over the weekend continued into Monday after Defense Secretary Pete Hegseth pledged an “unrelenting” campaign until the group stops attacking vessels in the Red Sea.

Yemen's Houthi rebels say there have been fresh US strikes against them, with the number of dead rising to 53, including five children. Targets in the Al Jaouf and Hudaydah areas were hit early on Monday, according to the rebel group, while the US Central Command said its forces had continued operations.