Eleven people have been killed and 19 wounded by a Saudi-led coalition air strike that hit a hospital in Yemen's northern Hajja province.

The coalition says it has launched a probe into the attack, amid mounting international condemnation of its airstrikes.

The air strike was the latest in a series of coalition raids that have hit civilian facilities, including a school on Saturday where 10 children were killed.

The coalition launched its bombing campaign in March last year, after Shiite Huthi rebels seized large parts of Yemen, including the capital Sanaa.