Britain's foreign minister says U.K. troops are helping identify targets for a Saudi-led military campaign in Yemen, and have not found any "deliberate" breaches of humanitarian law.

Britain's support for Saudi airstrikes has been criticized by human rights groups, who accuse Saudi Arabia, a Sunni Muslim kingdom, of bombing civilians in its campaign against Shiite Houthi rebels involved in Yemen's civil war.

Foreign Secretary Philip Hammond told lawmakers in the House of Commons Tuesday that he could not reveal how many British personnel were involved, "but we do have a military presence in Saudi Arabia and we are working with the Saudi Arabians ... to ensure that only targets that are legitimate military targets are struck."

He said there had been "no evidence of deliberate breach of international humanitarian law."