The United Nation's refugee agency has warned that as many as 700,000 people could have fled Syria by the end of the year, a huge increase on its previous estimate.
Some 294,000 refugees have already left Syria, and the UNHCR is appealing for money to help deal with the crisis, reports the BBC.
Most of the refugees are housed in camps in Turkey, Lebanon and Jordan.
A UK-based activist group says Wednesday was the bloodiest day of the 18-month-old conflict so far, with more than 305 peoplekilled.
Rami Abdel Rahman, from the Syrian Observatory for Human Rights, says the figure includes only those whose names had been documented, the BBC reports.
"If we count the unidentified bodies, the figure will be much higher," he says.
The group says 199 of Wednesday's dead are civilians.