Aid convoys arranged by local and international organisations have reached three besieged towns in Syria, where thousands are trapped and some have died of starvation.
The convoys are part of a deal between the government and rebels to let supplies into besieged areas.
Trucks first arrived to the rebel-held town of Madaya, located west of Damascus and near the Lebanese border. It has been under siege by government forces and Hezbollah fighters since July.
Aid convoys later reached two towns besieged by rebels in Idlib province, Fouaa and Kefraya.
The World Food Programme said the aid carried on the Madaya convoy will meet the needs of 40,000 people for one month.
Abou Ammar, a media activist in the town, said local aid organisations had been waiting since early morning for supplies to arrive.
"We have all been eagerly waiting since 5am. The situation here is getting worse and it's about time this operation goes through," he told Al Jazeera over the phone.
One person died due to starvation hours before the convoys arrived, he said, adding to reports of dozens of deaths related to hunger.
The UN refugee agency (UNHCR) said the first trucks arrived in a convoy of 49 vehicles.
"The first four trucks, carrying essentials including blankets and food packages of rice, oil and lentils were allowed into the town, where volunteers began unloading them in the dark, watched by groups of hungry people, including children," the agency said.
The operation to distribute aid was expected to take a few days, the spokesperson for the Red Cross delegation in Syria, Marianne Gasser, said.
"This is a very positive development. But it must not be just a one-off distribution. To relieve the suffering of these tens of thousands of people, there has to be regular access to these areas," she said.
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At least 400,000 are living under siege in 15 locations across Syria, according to the UN.
Doctors Without Borders (MSF) have said that at least 28 people, including six babies under one year of age, have died from hunger-related causes in Madaya.
MSF also said they have identified 250 people with severe acute malnutrition, including 10 patients who are in immediate need of lifesaving hospitalisation.
There are at least 42,000 people trapped in the town, according to the UN.
Mousa al-Maleh, the head of the local committee in Madaya, told Al Jazeera that the amount of aid delivered was less than what is needed.
"The amount of items that have arrived on these trucks are too little and will not be enough to last long. This is a joke. I call on the international community to help end this siege and help the people of Madaya," he said.
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The Shia towns of Fouaa and Kefraya have been under siege by Jaysh el Fateh - a collective of opposition groups that includes Ahrar al-Sham and al-Nusra Front - since March 2015.
Anas Maarawi, a media activist in Idlib, told Al Jazeera that four trucks arrived to the towns on Monday.
A child eats a fruit on the outskirts of tMadaya after aid is delivered [Louai Beshara/AFP]
"The rest are expected to be on their way in. We were told there are 16 others expected," he said.
Speaking shortly after the delivery of aid, Syria's ambassador to the UN, Bashar al-Jaafari, accused rebel groups of looting aid and Turkish authorities of obstructing deliveries.
"Some of the humanitarian assistance sent to restive areas has been looted by armed terrorist groups on several occasions and this is exactly what happened in Madaya and Zabadani.
"The Turkish authorities hindered the delivery of humanitarian assistance through their borders to other restive area."
Additional reporting by Diana Al Rifai. Follow her on Twitter @D_R_23
Source: Al Jazeera