(CNN) -- Dozens of children are among the latest victims of the Syrian civil war after barrel bombs fell on an elementary school Wednesday, dissidents said.
Syrian forces dropped the bombs on an opposition-held area of Aleppo, the country's largest city, the opposition Local Coordination Committees of Syria said. The LCC said 25 children died.
Barrel bombs typically consist of barrels stuffed with explosives and objects such as nails to maximize carnage. A video posted by opposition activists showed what appeared to be a pool of blood and a side of a building reduced to rubble.
Another concrete wall featuring a drawing of a child was peppered with holes. A pile of chairs and debris was covered in red.
CNN cannot independently verify the authenticity of the video.
The state-run Syrian Arab News Agency made no mention of such an attack on its website Wednesday. Instead, it featured a story about President Bashar al-Assad and his wife hosting a reception for parents of sons who died while defending the "homeland."
"The citizens' willingness to offer the most precious issue they own to defend Syria and not allowing to sabotage it was one of the most important reasons behind steadfastness of the country in the face of most powerful powers," al-Assad said, according to SANA.
Al-Nusra claims responsibility for attack
The jihadist group al-Nusra Front claimed responsibility Wednesday for twin car bombings the day before that killed at least 79 civilians in the al-Zahra neighborhood of Homs, dissidents said.
Another 21 fighters from the government-funded, Alawite-manned National Defense Force were killed, the opposition Syrian Observatory for Human Rights said.
The dual blasts Tuesday were among the deadliest attacks in an Alawite-dominated area. Al-Assad is a member of the Alawite religious sect, which is an offshoot of Shia Islam.
Al-Nusra detailed the attack in a statement Wednesday.
"The first car was detonated on time in order to kill the maximum number of Shabiha (al-Assad's militiamen) in addition to the huge material damage," the statement read.
As rescuers rushed to the scene, "the second car bomb detonated, blasting their hideouts to be the knockout punch that finished off whoever survived the first explosion since the two cars were parked in a manner aimed to cause the highest casualty number possible in their ranks so they can live the pain and suffering our people have been living."
Al-Nusra ended its statement with an ominous threat: "We promise the Alawites and all of those who support them that there will be MORE to come."
Presidential election looming
Al-Assad, whose family has ruled Syria for 43 years, recently registered his candidacy for another term.
The president succeeded his father in 2000 and won a second term in 2007, unopposed.
Syria's presidential election is scheduled for June 3. As of Wednesday, 17 candidates have registered, SANA said.
But the United Nations is asking the government to reconsider the election as the carnage continues to mount every day.
Well over 100,000 people, including many civilians, have died in Syria's three-year civil war, the United Nations said. On Wednesday alone, at least 29 people were killed, the LCC said.
So far, all attempts to stop the fighting between government forces and rebels seeking al-Assad's ouster have failed.