Arab foreign ministers denounced on Wednesday "crimes against humanity" being perpetrated in Syria, and called on the Damascus government to stop the violence immediately.
They also condemned "violence and killings of civilians from any side" in a veiled reference to rebels battling the regime of Syrian President Bashar al-Assad.
Capping an ordinary meeting in Cairo, the ministers condemned "the pursuit of violence, killings and ugly crimes carried out by the Syrian authorities and their shabiha militias against Syrian civilians."
"The Syrian government must stop immediately and completely all forms of violence and killings against the Syrian people," the statement said.
"The crimes and massacres being carried out are crimes against humanity," said the ministers.
"The UN Security Council must take all the necessary measures to bring to international justice all those responsible for these crimes," the added.
The ministers also denounced Syrian authorities for unleashing heavy weapons against residential areas.
At least 26 000 people have been killed since the uprising against the Damascus regime erupted in March 2011, according to the Syrian Observatory for Human Rights.
The ministers expressed "deep concern for the deteriorating humanitarian conditions in Syria, which has forced the displacement of 2.5 million people, while hundreds of thousands were forced to flee to neighbouring countries.
According to the UN refugee agency, the number of Syrian refugees rose sharply last month, with more than 100 000 fleeing to seek refuge in neighbouring countries.
It was the highest monthly figure since the conflict erupted in March last year, UNHCR spokeswoman Melissa Fleming told reporters in Geneva.
The total number of refugees who have been registered or are awaiting registration in neighbouring countries now stood at 235 000, she added, with most of them seeking shelter in Jordan, Turkey and Lebanon.
Arab foreign ministers also asked Qatari Prime Minister Hamad bin Jassem, who heads a ministerial committee on the Syrian crisis, to hold talks with international envoy Lakhdar Brahimi to discuss a new impulse for his mission.
Brahimi, a former Algerian foreign minister who took up his post on Saturday, said the 18-month old war was "deteriorating steadily" and described the death toll as "staggering."
Egyptian President Mohamed Morsi earlier 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.
"I tell the Syrian regime 'there is still a chance to end the bloodshed'. Now is the time for change... no time to be wasted talking about reform," Morsi told the Cairo meeting.
"The Syrian blood that is being shed day and night, we are responsible for this," Morsi said. "We cannot sleep while Syrian blood is being shed."
"I call on you, Arab foreign ministers, to work hard to find an urgent solution to the tragedy in Syria," Morsi said.