An international rights group says a Saudi-led coalition's offensive against Shiite rebels along Yemen's west coast has displaced tens of thousands of Yemeni civilians.

Thursday's report by Amnesty International says Yemeni escapees described "terrifying mortar attacks, air strikes, landmines and other dangers" as coalition forces attempt to retake the rebel-held areas along the country's west coast.

Amnesty says the coalition's offensive has sent Yemenis fleeing to government-held areas including Aden, warning that "the worst could be yet to come."

Citing the United Nations, the report says fighting along Yemen's west coast has displaced 100,000 people in recent months, mostly from Hodeida province.

The Saudi-led coalition backing an internationally recognized government has been at war with the Iran-allied rebels known as Houthis in Yemen for more than three years.