WARNING: Many of the following slides contain extremely graphic images.
In one of the most iconic images yet to come out of Syria's civil war, a band of rebels in an outpost in Aleppo are captured in this video frame at the exact moment a tank shell slammed into them. The only survivor, in addition to the photographer, was the one in dark silhouette, closest to the camera. Global Post's Tracey Shelton said she was filming a feature on life on the frontlines of Aleppo, camping out with the men of Noor Den al-Zenke batallion, in a two-block stretch of backstreets that had formed the final line between government troops and opposition forces. The men had been warned a tank was approaching, and were grabbing their weapons when a shell hit.
This citizen journalism image provided by Aleppo Media Center AMC, which has been authenticated based on its contents and other AP reporting, shows people searching through the debris of destroyed buildings in the aftermath of a strike by Syrian government forces, in the neighborhood of Jabal Bedro, Aleppo, Syria, Tuesday Feb. 19, 2013. Aleppo, which was Syria's largest city before refugees fled en masse, has been the scene of intense fighting, and therefore destruction, as both sides know control of the city is the key to winning the war.
Smoke rises in the Hanano and Bustan al-Basha districts in the northern city of Aleppo on December 1, 2012. The Aleppo rebellion started off in the rural areas of Aleppo province, not in the city as was the case in most other parts of Syria. Regime forces punish the city daily with artillery and airstrikes. Civilians are killed and wounded while standing on breadlines, walking the streets or watching television at home. Snipers target civilians in areas where rebels have positions. Members of staff at the rebels' field hospital say 80 percent of the average 100-120 cases they treat daily are civilians. Some residents blame the rebels.
Smoke billows from burning tyres as a Syrian rebel of the Halab al-Shabah battalion under Al-Tawhid brigade fires towards regime forces during clashes in Al-Amariya district of the northern city of Aleppo on November 13, 2012. Fierce battles and army shelling in and near Damascus killed at least 41 people that week, mostly civilians, the Britain-based Syrian Observatory for Human Rights said, as warplanes launched more air raids on a town on the Turkish border.
Syrian people take cover as a second bomb explodes while civilians were undertaking a rescue attempt in a nearby building that was hit by a previous bomb during an air raid by government forces, on November 4, 2012, on the northern Syrian city of Al-Bab, 40 kilometers north-east of Aleppo. An AFP correspondent reported three air strikes in close succession on the town of Al-Bab.
Syrian women walk past destruction in the Baba Amr neighbourhood of Homs on May 2, 2012.
A man checks a woman's wrist for a pulse after a huge explosion at a security checkpoint in central Damascus that officials blamed on "terrorists" -- the Assad regime's term for rebel militias -- Feb. 21, 2013, in this image from the Syria's state news agency SANA. The car bomb shook central Damascus, exploding near the headquarters of the ruling Baath party and the Russian Embassy, eyewitnesses and opposition activists said.
This photo released by the Syrian official news agency SANA, shows Syrian security agents carrying a body following a huge explosion from a suspected car bomb that shook central Damascus, Syria, Thursday, Feb. 21, 2013.
An image taken from video posted to YouTube by Syrian opposition activists purportedly shows incendiary submunitions burning in a playground in the town of Quseir, Dec. 3, 2012. The content of the video could not be independently verified, but came amid opposition reports of incendiary devices being used by government forces in the area.
A Syrian rebel fighter kisses a Koran, Islam's holy book, that was found in the rubble of al-Kheir mosque that was hit by a tank shell on October 26, in the Old City of Aleppo on October 28, 2012.
A Syrian fireman tries to extinguish fires at the scene of two huge bomb explosions outside the Palace of Justice in Central Damascus on June 28, 2012. A police source told AFP on condition of anonymity that two magnetic bombs exploded in two judges' cars in the open-air car park, while a third was in the process of being defused. It was unclear at the time who was behind the bombing, although regime officials repeatedly blamed the rise in al Qaeda affiliates, and al Qaeda operatives from Iraq, who are sympathetic to the rebels' cause and eager to establish another Islamic state, on the increase in bombings in Damascus.
Syrian security personnel investigate after a bomb attached to a fuel truck exploded outside a hotel where U.N. observers were staying in Damascus, Syria, Aug. 15, 2012.
Syrian soldiers check a burned truck in front of a damaged military intelligence building where two bombs exploded, at Qazaz neighborhood in Damascus, Syria, on May 10, 2012.
WARNING: The following slides contain extremely graphic images.
A Syrian man shows marks of torture on his back, after he was released from regime forces, in the Bustan Pasha neighbourhood of Syria's northern city of Aleppo on August 23, 2012. Even before the war, the Assad regime was often accused of employing torture on its prisoners.
Syrian mourners pray over the bodies of civilians, who were executed and dumped in the Quweiq river, during their burial at a park now renamed "Martyrs of the River" park in the Bustan al-Qasr district of the northern city of Aleppo on January 31, 2013. The bodies of dozens of young men, all executed with a single gunshot, were found in the river this week, adding to the grim list of massacres committed during Syria's conflict.
Syrian security forces stand guard as a medic carries a body found at a mass grave in Jisr al-Shughur, about 200 miles northwest of Damascus, on June 15, 2011. Syrian state television said earlier that 120 policemen had been massacred in the town "by armed terrorist groups in Jisr al-Shughur." The bodies were retrieved from under a pile of garbage. The U.N. Commission of Inquiry on Syria released a 131-page report Monday, Feb. 18, 2013, detailing deepening radicalization by both sides and says fighters on both sides in Syria's civil war have committed atrocities and should be brought to justice.
This citizen journalism image provided by Shaam News Network SNN, taken on Sunday, Aug. 26, 2012, purports to show people killed by shabiha, pro-government militiamen, being buried in a mass grave in Daraya, Syria. The shabiha are armed men in civilian clothing who have been doing the Assad regime's dirty work for many years. Their direct links to the government are a source of much dispute and debate.
A relative holds a body of a 6-year-old Syrian boy Bilal el-Labloubi during his funeral in Ramtha, Jordan, Friday July 27, 2012. The boy was allegedly shot dead by the Syrian army as his parents and a dozen other refugees tried to cross a border to seek refuge in Jordan, his mother said.
A Syrian man cries while holding the body of his brother, killed by Syrian Army shelling, near Dar al-Shifa hospital in Aleppo, Syria, on Oct. 11, 2012.
Abu Ibrahim carries the body of his brother after he was killed fighting Syrian government forces near Idlib in northern Syria in early 2012.