BATTLE SCARSBattle of Aleppo Rages On: Inside the Ravaged Syrian City (PHOTOS)01.17.13BATTLE SCARSBattle of Aleppo Rages On: Inside the Ravaged Syrian City (PHOTOS)As violence mounts in Aleppo a day after a deadly explosion at a university, see photos from the war-torn city.01.17.13 9:45 AM ETAchilleas Zavallis/AFP/Getty Just one day after a deadly explosion at Aleppo University that killed at least 87 and wounded 200 others, the Syrian city is still reeling. The incident is the latest in an interminable 22-month revolt against President Bashar al-Assad—a ruthless effort that has led to the deaths of an estimated 60,000. On Wednesday U.N. Secretary-General Ban Ki-moon denounced the escalating violence in Syria, calling it “heinous” and “unacceptable.” As violence mounts in Aleppo, a harrowing look inside the war-torn city. Andoni Lubaki/AP A Free Syrian Army fighter aims his weapon in the Saif al-Dawlah neighborhood of Aleppo. A deadly mortar attack struck the neighborhood, killing several children, in early January. Achilleas Zavallis/AFP/Getty The body of a wounded person is pulled from the rubble of a building targeted by a missile in the al-Mashhad neighborhood of Aleppo. The violence in Syria has triggered a “staggering” humanitarian crisis, according to the International Rescue Committee. Andoni Lubaki/AP Men help a wounded civilian after a mortar attack in the Saif al-Dawlah neighborhood of Aleppo. The revolution against the Syrian regime, which began in March 2011 with peaceful protests, has morphed into a nearly two-year civil war. Olivier Voisin/AFP/Getty A rebel fighter prepares the wires of a car-mounted camera used to spy on Syrian government forces while his comrade smokes a cigarette in the Bab al-Nasr district of Aleppo’s old city. Syria’s domestic opposition snubbed a call from Assad, as NATO powers challenged the leader’s defiant grip on power and dispatched Patriot missile batteries to neighboring Turkey. Muzaffar Salman/Reuters, via Landov An internally displaced Syrian man shows a scar on the back of a child, Mohamed. The man said the mark was from a wound inflicted during shelling at the school where they were staying in Aleppo. Olivier Voisin/AFP/Getty TV monitors broadcast the live feed from a camera situated on an electric car used by rebel fighters to monitor Syrian government forces in the Bab al-Nasr district of Aleppo’s Old City. Georgette, 75, drinks tea in the living room of the St. Elie Rest Home, founded in 1863 in Aleppo. The aging Syrian Christians holed up inside the retirement home in the devastated Aleppo have no light, no telephone lines, and little idea of what is happening in the outside world. Achilleas Zavallis/AFP/Getty A Syrian rebel sniper takes his position during clashes with government troops defending the Minakh military airport near Aleppo. U.N.–Arab League peace envoy Lakhdar Brahimi stressed the urgency of ending the Syrian conflict after meeting with top U.S. and Russian officials, but reported no concrete advances toward a solution. Andoni Lubaki/AP A Free Syrian Army fighter aims his weapon during clashes with government forces in Aleppo following the two explosions that struck the main university in the city. At least 87 people, mainly students, were killed, and up to 200 wounded. Andoni Lubaki/AP A street controlled by government forces is seen through a sniper’s crosshairs in the city’s Saif al-Dawlah neighborhood. Syrians have refused to surrender in their fight to overthrow Assad, who in a rare address just a week ago acknowledged the suffering of his people. Muzaffar Salman/Reuters, via Landov People gather at a site hit by what activists claim were missiles fired by a Syrian Air Force fighter jet from forces loyal to Assad. Activists continually attempt to lay siege to government airports, a move that—if successful—would cut off Assad’s key advantage: airstrikes. Andoni Lubaki/AP Syrian civilians, one draped in the revolutionary flag, walk through the ruins of a destroyed home in Aleppo. While some have chosen to stay in their war-torn neighborhoods, tens of thousands of others are battling frigid temperatures in makeshift refugee camps.