The U.S. has launched a fresh airstrike on a Houthi rebel radar instillation, in what was described as a follow-up attack to an earlier barrage across Yemen intended to degrade the group’s ability to target commercial shipping in the Red Sea.

Unlike the previous operation, in which the U.K. took part with support from several other nations, this one was conducted solely by the U.S., two officials said Friday night, asking not to be identified ahead of an announcement.

Earlier in the day, President Joe Biden had warned the Houthis and Iran, which supports the group, that he wouldn’t be afraid to launch more strikes.