GENEVA/SANAA (Reuters) – Humanitarian aid workers and medical supplies began to arrive in the Yemeni capital of Sanaa on Saturday, U.N. officials said, after the easing of a nearly three-week-old military blockade that caused an international outcry.

International aid groups have welcomed the decision to let aid in, but said aid flights are not enough to avert a humanitarian crisis. About 7 million people face famine in Yemen and their survival depends on international assistance.

“First plane landed in Sanaa this morning with humanitarian aid workers,” WFP’s regional spokeswoman Abeer Etefa told Reuters in an email, while officials at Sanaa airport said two other U.N. flights had arrived on Saturday.

The United Nations children’s fund (UNICEF) said one flight carried “over 15 tonnes” of vaccines that will cover some 600,000 children against diphtheria, tetanus and other diseases.

“The needs are huge and there is much more to do for

#YemenChildren,” the world body said on its Twitter account.

Airport director Khaled Al Shayef said that apart from the vaccinations shipment a flight carrying eight employees of the International Committee of the Red Cross had also landed.

“Sanaa airport was closed from Nov. 6 until today, more than 18 days and this closure caused an obstruction to the presence of aid workers,” Shayef told Reuters television in Sanaa.

“There are more than 500 employees trapped either inside or outside being denied travel as well as 40 flights that were denied arrival at Sanaa airport,” he added.

The Saudi-led coalition fighting the armed Houthi movement in Yemen said on Wednesday it would allow aid in through the Red Sea ports of Hodeidah and Salif, as well as U.N. flights to Sanaa, but there has been no confirmation of any aid deliveries yet.

FAMINE

A spokesman for the U.S.-backed coalition said in a statement issued on Friday that 82 permits have been issued for international aid missions since Nov. 4, both for the Sanaa airport and Hodeidah, the country’s main port where some 80 percent of food supplies enter.

“That includes issuing clearance for a ship today (Rena), carrying 5,500 Metric Tons of food supplies, to the port of Hodeidah,” coalition spokesman Colonel Turki Al Maliki said in a statement issued in a status update published by the Saudi embassy in Washington.

Officials at the port said on Saturday that no ships have arrived yet and they were not expecting any to dock soon.

The coalition closed air, land and sea access in a move it said was to stop the flow of arms to the Houthis, who control much of northern Yemen, from Iran.

The action came after Saudi Arabia intercepted a missile fired toward Riyadh. Iran has denied supplying weapons.

The blockade drew wide international concern, including from the United States and the United Nations secretary-general.

Sources in Washington said that U.S. Secretary of State Rex Tillerson had asked Saudi Arabia to ease its blockade of Yemen before the kingdom decided to do so.

The heads of three U.N. agencies had earlier urged the Saudi-led military coalition to lift the blockade, warning that “untold thousands” would die if it stayed in place.

The coalition has asked the United Nations to send a team to discuss ways of bolstering its UNVIM programme which was agreed in 2015 to allow commercial ships to enter Hodeidah.

The coalition joined the Yemen war in March 2015, after the Houthis forced President Abd-Rabbu Mansour Hadi and his government to flee their temporary headquarters in the southern port city of Aden into exile in Saudi Arabia.

The Yemen was has killed more than 10,000 people and displaced more than two million, caused a cholera epidemic that had affected nearly one million people, and drove Yemen to the verge of famine.

(Reporting by Stephanie Nebehay; writing by Sami Aboudi; editing by Alexander Smith)