BEIRUT (AP) — Aid workers failed to evacuate anyone from blockaded rebel-held neighborhoods in the central Syrian city of Homs on Tuesday or deliver any food, increasing pressure on them to complete the ambitious humanitarian operation before a fragile truce expires, activists and Syrian Red Crescent officials said.

Over 1,000 civilians have already left the embattled districts, which have been under siege for 20 months by government forces and suffer from widespread hunger. The three-day truce that allowed the U.N-Red Crescent operation was extended to six days, now expiring at midnight Wednesday.