A?bomb ripped through a high-level security meeting in the Syrian capital yesterday, killing the defense minister as well as President Bashar Assad's brother-in-law in the harshest blow to the government's inner circle in the 16-month uprising.

(L-R) Former Syrian Defence Minister General Hassan Ali Turkmani, Defence Minister Dawood Rajiha and Assef Shawkat, the brother-in-law of Syrian President Bashar al-Assad are seen in this combination photo. [Photo/Agencies]

Syrian Defense Minister Dawood Rajha, and his Deputy, Assef Shawkat were killed in the bombing as Assistant Vice-President Hassan Turkmani died hours later of serious wounds. Shawkat is also the president's brother-in-law.

Syrian Interior Minister Mohammed Ibrahim al-Shaar was also injured by the blast.

The high-level assassinations could signal a turning point in Syria's civil war as the violence becomes increasingly chaotic.

Syria's rebel commander, Riad al-Asaad, said his forces carried out the attack. Although state-run TV said it was a suicide blast, al-Asaad said his rebel forces planted a bomb in the room and detonated it. All those involved in carrying out the attack are safe, he said.

Right after the blast, security and army forces beefed up presence and fanned out around the area.The ministry of defense pledged tough response for the bold attack, Xinhua reported.

In a statement carried by the state TV, the ministry pledged to eradicate the armed groups and their hideouts, adding that the recent attack will only strengthen the forces' resolution to eliminate the terrorists across the country.

Meanwhile, Information Minister Omran Zoubi said the morale of the Syrian army is high, refuting media claims circulated on Arab TV which said that the spirit of the Syrian army is low and that many defections have happened after the blast.

He said that Syria is capable of retaliation, adding that what happened is the work of the countries which support the armed groups in Syria with money and arms. Just a couple of hours after the blast, a new defense minister was appointed by Assad.

As night started to fall, almost all the shops of the capital closed their shutters and the city appeared deserted except for the sounds of firefights and the hovering helicopter gunships, which have been apparently taking part in the wide-scale offensive the government has launched to regain control of rebellious neighborhoods and suburbs of Damascus.

The capital has been witnessing a surge in clashes between the government troops and the armed rebels since Sunday.

The rebel Free Syria Army said the "greater battle" of Damascus has already begun and they have used a new tactic to launch a number of simultaneous attacks in many areas and reportedly set tires ablaze to distract the Syrian army's attention.

Witnesses said heavy clashes took place in the areas of Kafr Souseh, Midan, Tadamun, Nahr Aisha and others.The intensity of the clashes have disturbed the nights of the capital, which has been bustling with people roaming its streets till dawn.

Internationally, Russia strongly condemned the brazen attack in Syria, considering the attack another attempt to destabilize the situation in the unrest-stricken country.

Also, US Defense Secretary Leon Panetta said Wednesday the situation in Syria was fast "spinning out of control," and called for more international pressure on Damascus.

In a joint press conference with visiting British counterpart Philip Hammond, he said the violence in the Middle East country had "only gotten worse and the loss of lives has only increased," leading to a situation "that is rapidly spinning out of control."

Meanwhile, the United States imposed sanctions against 29 senior Syrian officials on Wednesday. Syria's ministers of finance, justice and health and the governor of the central bank were among these officials targeted by the US Department of Treasur

Witnesses said the Syrian troops have ramped up attacks on opposition strongholds, while pro-government media said some 30 armed men were killed Wednesday in the Midan neighborhood.

The severity of the capital's clashes have added a heavy blow to the 16-month bloody unrest, as the state media is calling on people not to listen to media fabrications aiming at undermining the current administration.