It comes after the country's interior minister admits that police "lost control" in some cities.

Serhii Beskrestnov says there has not been enough time to warn people about incoming missile attacks. The White House said there had been no changes to intelligence sharing.

The Saudi government did not immediately respond to BBC requests for comment.

Three missiles hit a camp in government-controlled Shabwa province that officials say was being used as a training centre for new recruits.