A five-day humanitarian ceasefire has started in embattled Yemen, where Saudi-led coalition airstrikes have been targeting Shiite Houthi rebels and their allies.

The pause began at 11:59 p.m. (2059 GMT, 4:59 p.m. EDT) Sunday. It is intended to help allow aid to be delivered to ease the suffering of civilians in the Arab world's poorest country.

The Saudi-led coalition made the unexpected announcement about the humanitarian pause on Saturday. The statement, carried on Saudi state media, said the coalition will cease military operations, but that it will respond should Houthi rebels or their allies conduct any military actions or movements.

The rebels have expressed doubt over the truce.

It wasn't immediately clear if the two sides were honoring the cease-fire. Two other humanitarian truces in Yemen did not hold.