The UN refugee agency says there are now more than 100,000 Syrian refugees in Lebanon.
Agency spokeswoman Melissa Fleming said that at least 101,283 Syrian refugees are registered in Lebanon, joining the more than 105,000 registered in Jordan and 101,000 in Turkey.
There are also more than 42,000 Syrian refugees in Iraq.
Fleming called for international support for countries hosting these refugees, saying, "These nations should not be expected to bear the burden alone."
In Jordan, where authorities claim there are more than 200,000 Syrian refugees, a group of angry Syrians burned some 20 tents on October 22 to protest poor living conditions.
A local charity organization helping the refugees said the incident occurred at the Zaatari desert refugee camp in northern Jordan.
Meanwhile, an antiaircraft shell fired from Syria reportedly hit a health center inside Turkey.
There are no immediate reports of injuries.
Turkish media said the shell landed in the Reyhanli district of Turkey's Hatay Province.
Tension between the two neighbors has escalated since October 3, when a shell struck a Turkish border town, killing five civilians.
Turkey has bolstered its military presence along its 900-kilometer border with Syria. Turkish artillery has been responding to repeated mortar and shelling from Syria.
Based on reporting by AP and Reuters