The National News Agency, run by the Lebanese government, reported the attack on the camp in the Bekaa Valley Saturday wounded nine people in addition to those killed, CNN said. The wounded were taken to Universal Hospital in Baalbek.
The agency said the dead included women and children.
The ambush occurred on Syrian territory near the Lebanese town of Arsal, a security source told The (Beirut) Daily Star. At least nine people were injured and were also in Universal Hospital.
The pro-rebel group Syrian Network for Human Rights said in a release from its offices in London that 106 people were killed by the fighting in Syria Saturday, including 13 who were tortured.
The group, whose figures are not independently substantiated, said the fatalities included 14 children and six women.
Forty-one of the deaths occurred in Damascus and the surrounding environs, the group said.
About 600,000 Syrian refugees are believed to be in Lebanon. The Syrian government charges that arms and fighters cross the border to carry on the civil war.
United Nations officials once again called for an end to the fighting Friday.
"The continued failure by parties to the conflict to protect civilians across Syria means that women, men, and children continue to be killed, injured and displaced across the country," Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator Valerie Amos said in a statement.