Smoke rises from eastern Ghouta in Damascus, Syria March 10, 2018. Sana/Handout via REUTERS THIS IMAGE HAS BEEN SUPPLIED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THIS IMAGE.

BEIRUT (Reuters) - Civilians in need of medical treatment left Syria’s besieged eastern Ghouta enclave for the second straight day on Wednesday under a medical evacuation agreement, a rebel official said.

Yasser Delwan, head of political affairs with the Jaish al-Islam rebel faction in eastern Ghouta, said around 25 patients had left the enclave on Wednesday. “So far the agreement is going well,” Delwan added.

Syrian state TV said a new batch of residents crossed out of the opposition-held area through the al-Wafideen corridor, although it did not specify whether the evacuations were for medical reasons.

The Syrian government has been trying to capture eastern Ghouta, the last big opposition-held area near Damascus, in a fierce offensive that began in mid-February. The battle has become one of the bloodiest of the war, with rebels on course for their worst defeat since the battle of Aleppo in 2016.

A group of sick and injured civilians left eastern Ghouta on Tuesday under the first medical evacuation since the offensive began.

The United Nations says 400,000 civilians are trapped in eastern Ghouta with little food or medicine, and has called for the urgent evacuation of 1,000 people for medical reasons.