Arab foreign ministers called Wednesday on the Syrian government to immediately stop the violence and denounced the killing of civilians by both opposition and government forces, dpa reported.
"We condemn the violence and killings of civilians from any side," the Arab foreign ministers said in a statement after concluding their meeting in Cairo.
"The Syrian government must stop immediately and completely all forms of violence and killings against the Syrian people," the statement said.
The conferees called on the UN Security Council to take "all the necessary measures to bring to international justice all those behind crimes against humanity," the statement added.
The ministers also expressed "deep concern for the deteriorating humanitarian conditions in Syria," which according to the UN has forced the displacement of 2.5 million people and pushed hundreds of thousands to flee to neighbouring countries.
The UN refugee agency said the month of August witnessed a rise in the number of refugees, with more than 100,000 fleeing to seek refuge in Lebanon, Jordan, Turkey and Iraq.
The ministers also tasked Qatari Prime Minister Hamad bin Jassem, who heads a ministerial committee on the Syrian crisis, to hold talks with Lakhdar Brahimi, the new international envoy to Syria, and find new ways to end the sufferings of the Syrian people.
Earlier, Egyptian President Mohamed Morsi told the ministers it was time for the Syrian regime to step down and added that a resolution of the crisis was an Arab responsibility.
"Now is the time for change ... You will not stay (in power) for longer," Morsi said at a meeting of the Arab League foreign ministers in Cairo.
"The Syrian people have made their decision. There is no room for delay in taking a crucial decision to stop bloodshed and usher Syria into change," Mosri said.
Morsi was elected in June as Egypt's first Islamist leader following an uprising that toppled Hosny Mubarak.
The president called on Arab diplomats to move quickly to resolve the Syrian conflict, which has left around 26,000 people dead, according to the opposition Syrian Observatory for Human Rights.
The Egyptian president last week lashed out at the Syrian regime at the summit of the Non-Aligned Movement which was held in Iran, al-Assad's main regional ally.
The head of the Arab League, Nabil al-Arabi, called the Syrian crisis an "unprecedented humanitarian and political tragedy."
"Fighting should be halted on both sides so that Mr Lakhdar Brahimi can make successful efforts to reach a formula ensuring power transfer and the beginning of a transitional stage (in Syria)," al-Arabi said in Cairo.
Brahimi, a veteran Algerian diplomat, replaced Kofi Annan as the Arab League-United Nations envoy for Syria. He is expected in Cairo on Sunday for talks with Arab League officials and some Syrian opposition politicians, his deputy Nasser al-Qodwa said.
Addressing the UN General Assembly meeting Tuesday, Brahimi called for unity in addressing the Syria crisis, saying the death toll in the conflict was "staggering."
On the ground in Syria, activists reported that more than 180 people were killed across Syria, most of whom were in the northern province of Aleppo, as government forces intensified shelling attacks on the rebel-held areas in the city.
Syrian state television quoted an unnamed military commander as saying that Aleppo "will be free of terrorists in 10 days."
Al-Assad's troops and rebels have been fighting for two months for the control of Aleppo, which is Syria's biggest city.
Syrian rebels also reported heavy fighting near Hamdan military airport in the eastern province of Deir al-Zour near the border with Iraq.
The rebels have stepped up their attacks on military air bases in northern province of Idlib and Aleppo, which are being used by the government forces to shell areas in both regions.
Unconfirmed reports said rebels are now controlling the Hamadan military airport in Deir al-Zour after many of the soldiers defected.
The London-based Syrian observatory for Human Rights said heavy clashes were reported in the al Yarmouk Palestinian Refugee camp inside the capital Damascus.
It added that a bomb planted in a car exploded in the region of Barakmeh in the capital Damascus, inflicting casualties. "Initial reports are indicating that there are wounded," it said.
Rebels also claimed they have shot down a helicopter at the outskirts of the capital Damascus.