A surge in violence in the restive city of Homs has killed up to 50 people in the past 24 hours, leaving dozens of bodies in the streets, activists said Tuesday.

Turkey's prime minister said Tuesday that Syria's president must step down over the country's crackdown on dissent, ratcheting up the pressure on the increasingly isolated Bashar Assad, as Syrian activists reported that four children were killed by security forces.

Rocket-propelled grenades struck the headquarters of Syria's ruling party Sunday, bringing the violence that has engulfed much of the country to the heart of its capital for the first time, activists said.

Dozens of soldiers and security forces were gunned down by suspected army defectors in southern Syria, a deadly ambush that comes as President Bashar Assad increasingly appears unable to manage the crisis, activists said Tuesday.

Syria's embattled regime called for an urgent Arab summit Sunday as it faced growing isolation — not only by the West but by its neighbors — amid mounting pressure to end its bloody crackdown against an eight-month uprising.

Syrian security forces killed 13 people Friday in strikes against thousands of protesters who took to the streets to test whether President Bashar Assad's regime would abide by an Arab League plan to end violence, activists said.

Syrian President Bashar Assad has warned against Western intervention in his country's 7-month-old uprising, saying such action would trigger an "earthquake" that "would burn the whole region."

Syrian security forces opened fire Friday on protesters and hunted them down in house-to-house raids, killing about 30 people in the deadliest day in weeks in the country's 7-month-old uprising, activists said.
Yemeni government forces opened fire Tuesday on protesters in Sanaa, killing seven, a medical official said, a day after the capital witnessed its worst fighting in weeks.