(CNN) -- A day after attackers bombed a pro-government TV station, massive explosions shook the heart of Damascus near the Justice Ministry, state-run media said.
Two blasts occurred in a parking lot Thursday outside the Palace of Justice, which houses the ministry, Syrian state TV said. The Local Coordination Committees of Syria confirmed the blast and said it occurred in the Marja neighborhood of central Damascus.
At least three people were injured, and 20 cars were damaged, state TV said.
Video showed heavy smoke rising above buildings in Damascus. Firefighters battled a blaze at the site of the explosion.
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On Wednesday, bombers killed at least seven people in the headquarters of the al-Ikhbaria television station near Damascus, the state-run Syrian Arab News Agency reported. Three journalists and four security guards died, and the attackers ransacked and destroyed studios, the news outlet said.
There has been a flurry of attacks in Syria's major cities of Damascus and Aleppo in recent months, strikes that opposition groups have said the government has orchestrated to discredit anti-regime forces.
President Bashar al-Assad's regime has blamed the attacks on terrorists.
"Terrorist operations of this nature could not be implemented without adequate financing and support in terms of providing money, weapons or persons or through media and political coverage," Bashar Jaafari, Syrian ambassador to the United Nations, said Thursday.
"It is indeed regrettable that some Arab and regional states, as well as others, do provide these facilities to armed terrorist groups in order to undertake terrorist actions in my country."
The opposition Syrian Observatory for Human Rights said more than 140 people, 46 of them government forces, died in violence Thursday.
The Local Coordination Committees put the number at 100, but it counts only civilians and soldiers who defected.
Both opposition groups said many of the deaths occurred in Damascus suburbs, mostly in the town of Douma, and in Homs.
CNN cannot independently confirm the reports of casualties or violence because access by international journalists to Syria has been severely restricted.
State media said an armed terrorist group assassinated a doctor and several members of her family in a Homs suburb. It said that "competent authorities" fought the group, killing 10 and injuring 20.
The International Committee of the Red Cross said an ICRC and Syrian Arab Red Crescent team had been prevented from entering the hard-hit areas of Homs to help people Wednesday.
"The suffering experienced by the civilian population in Homs is being exacerbated by the fact that aid is still not reaching them," the Red Cross said.
Beatrice Mégevand-Roggo, the International Committee of the Red Cross' head of operations for the Near and Middle East, said there had been "an agreement with the authorities as well as an understanding with various opposition groups on a pause in fighting" in order to allow crews to evacuate civilians, the sick and the wounded, and to deliver aid.
"On the spot, however, agreed-upon conditions were not met, and the staff were unable to proceed."
A Syrian government official blamed "armed terrorist groups" for the problem, SANA reported.
It was the fifth time the terrorists "foiled efforts exerted by the International Committee of the Red Cross, the Syrian Arab Red Crescent and the local authorities in Homs city to evacuate the wounded people, children and people with special needs from Homs neighborhoods," the official said.
The U.N. World Food Programme is launching a program to provide food assistance to Syrians who've escaped the fighting and fled to Lebanon, Jordan and Iraq.
After more than 15 months, unrest in the Arab nation shows no sign of abating. Internationally, tension rose last week after Syria shot down a Turkish jet, an act deplored by NATO and many Western nations.
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World diplomats have been working to end the intensifying violence and restore peace.
An emergency meeting has been set for Saturday in Geneva, Switzerland, to deal with the crisis. Kofi Annan, the United Nations' and Arab League's special envoy for Syria, is gathering world diplomats with the goal of agreeing on a plan to end the violence in Syria that has left thousands dead.
The meeting will bring together top diplomats of the five permanent members of the U.N. Security Council -- China, France, Russia, the United Kingdom and the United States -- and Turkey. Envoys from the United Nations, the European Union and the Arab League also were invited.
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The meeting of the group, dubbed the Action Group for Syria, comes at a critical time for the country, which has been mired in an uprising since March 2011 that has pitted al-Assad's forces against rebels calling for his ouster.
A peace plan hammered out by Annan fell apart this month after both sides -- the Syrian government and the rebels -- accused the other of failing to abide by the terms to end the killing.
U.S. Secretary of State Hillary Clinton is among those who will attend the Geneva meeting.
She agreed to the meeting after speaking with Annan, who has "been working with key member states on a political transition plan," State Department spokeswoman Victoria Nuland said Wednesday.
"The secretary spoke to him yesterday and told him that we like and accept his transition plan, and we think it can form the good basis not only for a meeting -- the kind of meeting that he's been looking for to show international unity -- but also to help the Syrian people move forward," Nuland said.
Russia has opposed the idea that other countries dictate a political transition, insisting that it is a decision for the Syrians themselves. But Russian Foreign Minister Sergey Lavrov said in Moscow that a transitional period is "necessary for settling the Syrian crisis and establishing stable and generally acceptable rules and norms, which will satisfy all the Syrian groups."
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Iran has not been invited to the meeting. The United States was against Tehran's presence despite Annan's and Russia's positions that Iran must be involved in helping forge peace in Syria.
Lavrov says Iran is an "influential player in this situation" and it's a "great mistake" to exclude that country.
"It has been said publicly in Washington that the U.S. is categorically against Iran's participation," Lavrov said. "This is a manifestation of a double standard. When the Americans needed to settle some issues related to the security of their troops in Iraq and Afghanistan, they initiated contacts with Iran and agreed on something without any hesitations."
Annan also declined to invite Saudi Arabia, which backs the opposition. Russia did not want Saudi Arabia at the meeting.
The Geneva meeting will come one day after Clinton meets with Lavrov in St. Petersburg.
While in St. Petersburg, Clinton also plans to discuss Russian arms sales to al-Assad's regime, the State Department official told reporters this week.
A shipment of refurbished Russian helicopters headed for Syria had to turn around and return to Russia after its British insurance company dropped coverage on the ship carrying the aircraft.
Russia and China, permanent members of the Security Council, have major trade deals with Syria. Both countries vetoed a U.N. resolution calling for an end to the violence and a transition of power.
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CNN's Salma Abdelaziz, Chelsea J. Carter, Joe Sterling and Jill Dougherty contributed to this report.