A deadly attack Wednesday delivered the harshest blow yet to President Bashar al-Assad's regime, taking the bloodshed into his inner circle.
Three top officials were killed and a number of others were wounded in an explosion at a national security building in Damascus, state TV reported.
The attack came after several days of violence in the capital. At least 189 people were killed across the country on Wednesday, including 37 in Damascus and 69 in its suburbs, the opposition Local Coordination Committees of Syria said.
The officials killed were Defense Minister Dawood Rajiha; Deputy Defense Minister Assef Shawkat -- al-Assad's brother-in-law; and Hasan Turkmani, al-Assad's security adviser and assistant vice president, state TV reported.
Due to a translation error, an earlier version of this article erroneously reported that Interior Minister Ibrahim al-Shaar had been killed as a result of the explosion. Al-Shaar was injured in the blast, but he is alive and in stable condition, according to Syrian state television. CNN regrets the error.
The attack, which occurred during a meeting of ministers and security officials, was coordinated by rebel brigades in Damascus, said the deputy head of the opposition Free Syrian Army, Col. Malek al-Kurdi.
The government described it as a suicide bombing. But al-Kurdi said a remote control was used to detonate an explosive device that had been planted inside the meeting room.
Al-Assad quickly named Gen. Fahd Jassem al-Freij as defense minister, state-run news agency SANA said.
State-run SANA said the government has killed or captured a "large number" of terrorist infiltrators in Damascus and inflicted "heavy losses" on terrorists in Homs and Idlib.
Video from a Damascus suburb showed Syrians rejoicing after news spread of the bombing.
Soon after, the pro-government Shabiha militia took to the streets, attacking with knives, shooting and saying, "This is retribution for what you have done," according to an opposition activist in Damascus, who is going by the name Lena to protect her identity.
There were bodies in the streets around the Yarmouk, a Palestinian refugee camp, and people were too afraid to collect them, Lena said.
"The people are really scared," she said, adding that mosques were blaring the messages "Stay in your homes" and "God is great."
A Damascus resident said shootings occurred in Baghdad Street, a major road that includes branch offices of state security agencies.
In the neighborhood of Medan, where violence has raged in recent days, Free Syrian Army fighters "launched their biggest attack yet all over Damascus, in 17 points," said Abo Abdo, a rebel fighter. They were working to "disperse the regime's forces all over the capital," he said.
Syria, on the official Syrian Arab News Agency, said its armed forces "chased down terrorists who infiltrated" Medan, and "killed and arrested a large number of them. The military units also chased down terrorists who terrorized some families in the neighborhoods of al-Qaboun and Tishreen and forced them to leave their homes."
With the Syrian government restricting foreign journalists from gaining access to the country, CNN cannot independently confirm reports of violence or details about the attack.
The bombing took place in a building in Rawda Square, near al-Assad's home and the U.S. Embassy, which suspended its operations in February. Security officials and government spies have had a heavy presence in the area.
The bombing's repercussions spread from the capital of Syria to the capital of Egypt, where clashes erupted Wednesday between the Egyptian police and hundreds of protesters outside the Syrian Embassy. Some of them were chanting, "Down, Down, Bashar al-Assad!"
"We only wanted to remove the flag and replace it by the independence flag, but the Egyptian riot police started beating us so we pelted them with rocks," said Ahmed H. Aggour, an organizer of the protest in Cairo. "Next thing you know they fired an incredible amount of tear gas, several canisters landed on the British Embassy nearby."
He added, "We want people in Syria to see how we are supporting their cause here in Egypt."
Most of the protesters were Egyptian, Tarek Shalaby, an Egyptian activist and web designer at the scene.
Alla Mahmoud, a spokesman from the Interior Ministry, told CNN that 15 protesters were arrested. Some suffered minor injuries, from excessive inhalation of tear gas to bruises.
Meanwhile, U.S. President Obama called Russian President Vladimir Putin on Wednesday to discuss the Syrian situation, the White House said. "They noted the differences our governments have had on Syria, but agreed to have their teams continue to work toward a solution," it said.
A planned Security Council vote on a draft resolution on Syria was delayed at the request of Kofi Annan, joint envoy to Syria for the United Nations and the Arab League, until 10 a.m. Thursday, diplomats said.