But the incident pointed to the dangers of a conflict that has already polarized the region, stirring ancient rivalries and newer enmities.
“This is the latest manifestation of a worsening situation,” said Andrew Tabler of the Washington Institute for Near East Policy. “This is not the only place it is spilling over. It is spilling over into Jordan, into Lebanon. They’re shelling on a daily basis. The difference today is it’s the first time we have a country calling Assad out.”
In a statement issued before the Turkish retaliation, U.N. Secretary General Ban Ki-moon issued an appeal for restraint, warning that the incident demonstrated the risks the violence in Syria poses to the region.
“Syria’s conflict is threatening not only the security of the Syrian people but increasingly causing harm to its neighbors,” he said.
The strike followed more than a year of growing hostility between Turkey and Syria, former allies who have turned into bitter foes since Erdogan joined his Western allies in calls for Assad to step down. The tensions soared sharply after Syria shot down a Turkish jet in June, killing two pilots over international waters, according to Turkey, and within Syrian territorial waters, according to Syria.
Meanwhile, a surge in the levels of violence in Syria over the summer months has propelled tens of thousands of refugees into Turkey, straining government resources and heightening government frustrations with the failure of its Western allies to take tougher action against Assad.
The number is likely to grow as the violence continues to rage. The suicide attack in Aleppo signaled that the rebels are growing more sophisticated in their strikes against government targets, at a time when the regime is stepping up its assaults against rebel-held areas with aerial bombardments.
According to state media, two suicide bombers detonated car bombs containing more than 2,000 pounds of explosives in the city’s central Saadallah al-Jabri square shortly after 8 a.m., killing 34 people and injuring 122. A third explosion nearby occurred while officers were dismantling a bomb, according to the official Syrian Arab News Agency.
The target, apparently a military officers club, was completely demolished. The blasts also caused widespread damage to the surrounding area, ripping the facades off several buildings. State television showed the bodies of three men wearing military uniforms lying amid piles of debris.
SANA said civilians and military personnel were among those killed, but rebels claimed that all of the victims were members of the security forces, saying that the area represented a legitimate target because it had been turned into what rebel spokesman Mohammed al-Halbi called “a military barracks.” High-ranking officers were living at the officers club, and two government-owned hotels damaged in the blast were being used to accommodate Syrian and Iranian intelligence operatives, he said.
Responsibility for the attack was claimed by the Jabhat al-Nusra, a militant group that has carried out a string of suicide bombings in Damascus and Aleppo in recent months.
Colum Lynch at the United Nations and James Ball, Anne Gearan, Scott Wilson and Craig Whitlock in Washington contributed to this report.