Updated on Sunday at 11:45 am: A car bomb killed at least four people on Saturday evening near a gas station in eastern Lebanon's town of Hermel, according to caretaker Interior Minister Marwan Charbel.
The Al-Nusra Front in Lebanon, a group named after al-Qaeda's Syrian affiliate, claimed the attack on Twitter, saying it was a suicide bombing in response to Hezbollah's involvement in Syria.
"At least four people were killed and more than 15 wounded, two or three of them in critical condition," caretaker Interior Minister Marwan Charbel told al-Manar television station.
A security source told Reuters that, besides the three dead bystanders and the dead bomber, 28 other people had been wounded in the blast, which took place around 6:00 pm.
The proximity of the explosion to the al-Aytam gas station had sparked a huge blaze that hindered the arrival of emergency services, according to statements by a security source to NNA.
Security forces later closed off the area and firefighters managed to extinguish the blaze.
Lebanon's National News Agency (NNA) cited witnesses who said the perpetrator entered the gas station and asked to buy fuel before detonating the bomb, leaving a meter-deep hole in the ground and setting the station and nearby cars on fire.
According to the Lebanese National News Agency, the blast was also in proximity of a school hosting orphans. The al-Mabarrat school confirmed that none of their resident students were hurt
Caretaker Prime Minister Najib Mikati condemned the attack.
"Once again, the hands of treason target a Lebanese region and claim the lives of innocent citizens," he said.
Charbel, told Reuters by phone that the situation in Lebanon was "unstable and getting worse every day."
"This matter is very, very dangerous," he said. "It is bigger than the security apparatus."
Syrian Information Minister Omran al-Zohbi, speaking on satellite television channel Al-Mayadeen, said "this terrorist attack, like those before it, only benefits the Israeli enemy".
The United Nations Security Council issued a statement condemning the "terrorist attack" and calling for the perpetrators to be brought to justice.
Council members also appealed to all Lebanese people "to preserve national unity in the face of attempts to undermine the country's stability" and for all parties to refrain from any involvement in the Syrian crisis.
In a separate statement the UN secretary general's spokesman Martin Nesirky said Ban Ki-moon also strongly condemned the car bombing and extended his condolences to the bereaved.
"The recent escalation in acts of terrorism and violence in Lebanon is of grave concern," he said, adding that Ban called on all players, including the army and security forces, "to confront such unacceptable and indiscriminate actions and to safeguard their country's security and stability".
Tensions surfaced elsewhere in Lebanon after the explosion.
Residents of al-Labweh blocked the road to Ersal in protest of the recent explosion late on Saturday. While in Beirut, a hand grenade was thrown at the al-Manar's headquarters that same evening, according to a report by al-Mayadeen television channel.
Lebanon has witnessed multiple major car bomb attacks since July 2013. The country has seen almost a deadly bombing per week in January, with two explosions in Beirut's southern suburb of Haret Hreik.
A car bomb had previously hit Hermel on January 16, killing six and injuring 40. These previous attacks had also been claimed by the Lebanon branch of al-Nusra Front.