The air strikes late Thursday targeted positions of the Iran-backed Houthi insurgents at Jebel al-Nabishuaib, on the southwestern outskirts of rebel-held Sanaa, according to witnesses.

They said the area hosts bases for air defenses controlled by renegade troops loyal to former president Ali Abdullah Saleh, who is allied with the Shiite rebels.

The truce, for an initial period of three days, took effect just before midnight Wednesday to allow aid deliveries in Yemen, where the war has killed thousands and left millions homeless and hungry.

The coalition and Yemeni President Abedrabbo Mansour Hadi had vowed to respect the U.N.-sponsored truce, but accused rebels of violations, while Huthi media accused the alliance of continuing with air strikes.

Air raids also targeted rebels in the northern provinces of Jawf and Saada, witnesses and rebel media said.

Coalition spokesman Major General Ahmed Assiri said Friday that alliance warplanes were only conducting surveillance flights and “reactive” strikes, in response to rebel truce violations.

Patriot missiles shot down two rebel missiles fired in Marib, east of Sanaa Thursday, he said.

The Saudi-led Arab coalition intervened in March 2015 to support Hadi’s government after the Houthis overran much of the impoverished country on the southern tip of the Arabian Peninsula.

Five previous truce attempts failed but cautious optimism preceded the current pause after intensified international pressure following an escalation in fighting.

Nearly 6,900 people have been killed, more than half of them civilians, while another three million are displaced and millions more need food aid.