Yemeni military officials say the Saudi-led coalition launched a series of airstrikes along the Yemen-Saudi border that mistakenly killed and wounded forces allied with the government.

Local tribesmen say airstrikes by the Saudi-led coalition fighting Yemen’s Houthi rebels have killed 22 people, including children, in the country’s north.

Yemeni security officials and eyewitnesses say that fighting has erupted in the key port city of Hodeida, the first significant clashes since warring sides agreed to a U.N.-brokered cease-fire deal in December.