A massive car bomb wounded scores of people in the Beirut stronghold of the Shia militant group Hezbollah Tuesday.
Reuters reported medics saying several people were killed in the Lebanon bombing. However, officials did not confirm any fatalities.
The blast occurred in the car park of a supermarket in the capital's Bir el-Abed neighborhood.
It came as many Shia Muslims began observing the holy month of Ramadan, and is being viewed as likely fallout of the civil war raging in neighboring Syria.
Sectarian tensions in Lebanon have been high following Hezbollah's intervention in Syria in support of Syrian President Bashar al-Assad's forces.
The revolt against Assad is being led by Syria's Sunni Muslim majority.
Hezbollah parliamentary deputy Ali Meqdad said, "This is the work of agents trying to create strife in Lebanon."
Hezbollah supporters reportedly marched in the area after the blast, carrying pictures of Hezbollah chief Sheik Hassan Nasrallah and shouting sectarian slogans.
They shouted, "The Shia blood is boiling."