A day after two Grad rockets exploded  in a Shiite-majority Hezbollah district in Beirut, a rocket was fired at Israel from the southern Lebanese town of Marjaoun early Monday, Al Arabiya’s correspondent reported.
"An explosion was heard. Soldiers are searching the area. The cause is still being investigated," an Israeli military spokeswoman said. A second Israeli military source said the explosion was probably caused by a mortar.
The rocket launch could be heard from the Lebanese town of Marjaoun, about 10 km (six miles) from the Israeli border, residents in the Lebanese town said.
Two rockets were fired on Sunday at al-Shayyah area in the Lebanese capital, wounding at least five people. They were seen as a response to a speech by Hezbollah’s leader Hassan Nasrallah a day earlier, in which he committed to fighting on the side of the President Bashar al-Assad in Syria.
One rocket landed in the Mar Mikhael district on the southern edge of the capital, striking a car exhibit near a church on the street and causing all four casualties, a Lebanese army statement said. Another struck the second floor of an apartment in a building in Chiyah district south of Beirut, about two kilometers (one mile) away from Mar Mikhael. The apartment's balcony appeared peppered with shrapnel, but no one was wounded.
The state-run National News Agency said among the wounded in the Mar Mikhael blast were three Syrians.
A security official told The Associated Press that rocket launchers were found in woods in a predominantly Christian and Druse area in suburbs southeast of Beirut. The official spoke on condition of anonymity in line with regulations.
Assad is fighting to end a two-year revolt against his rule, and has gained support from Hezbollah with fighters from the Shiite group fighting alongside regime forces in Syria over the past week.
The Free Syrian Army denied  any involvement in the rocket attacks, blaming Hezbollah and the Syrian regime for the eruption of violence in Lebanon, Al Arabiya TV reported, citing the FSA's chief of staff.
Nasrallah on Saturday vowed “victory” in the fight against Syrian opposition fighters, saying his group is committed to its choice in the conflict and will accept all sacrifices and consequences of it.
Meanwhile, Arab League chief Nabil Al-Araby on Sunday urged Hezbollah to stop fighting alongside Syrian government forces, Reuters reported.
Araby also strongly condemned the Grad rockets attacks as well the ongoing clashes in Lebanon’s northern city of Tripoli between factions supporting opposing sides in Syria, which have left 25 people dead in the last week.