The UN has estimated that 40 percent of all Syrians now need humanitarian aid.
The number has gone up dramatically from 6.8 million people displaced in June to 9.3 million this month.
The latest figures come on a day of renewed violence in the war-torn country.
In Damascus, the Vatican embassy suffered a mortar attack. An official praised God that it had been so early there were no people inside.
In the al-Yarmouk neighbourhood in the south of the capital, home to a Palestinian refugee camp, there was another attack.
Amateur videos posted online showed the aftermath of what appeared to be an air attack in the city of Douma, close to Damascus.
On Monday bomb attacks on the Alawite homeland province of Latakia were uploaded by activists.