ICRC said a convoy of 13 trucks, including food parcels for 12,000 people, went into Douma — the largest and most populated town in the terrorist-held eastern Ghouta, located on the outskirts of the Syrian capital.
The convoy was supposed to deliver its relief supplies on Monday, but it could not enter the area due to heavy fighting.
ICRC spokeswoman Indy Sedky said the trucks crossed into Eastern Ghouta on Friday "after getting security guarantees from all parties to make sure no incident will happen during the presence of our team" there.
The ICRC is preparing additional supplies, including medical material, to be sent in a bigger convoy next week.
The Syrian government and Russia, Damascus' ally, recently intensified their clearance operations in Eastern Ghouta to rid the area of terrorists.
Government troops this week advanced from the east and were only about a mile away from linking with forces on the western side of Eastern Ghouta.
Nearly 400,000 people are believed to be inside Eastern Ghouta.
The most densely populated areas still under terrorist control include the towns of Douma, Harasta, Jisreen, Kfar Batna, Saqba and Hammouriyeh.
Eastern Ghouta has witnessed deadly violence over the past few weeks, with terrorists launching mortar attacks on the Syrian capital.
