Arab leaders are calling on Syrian President Bashar al-Assad to step down, promising him safe passage if he leaves the country.

Arab League ministers held an emergency meeting on Syria in Doha Sunday. They said they regret that all Arab and international efforts to stop the bloodshed in Syria have failed.

They said Mr. Assad should immediately give up power and that the Kofi Annan peace plan should now focus on a transitional government. The ministers also pledged $100 million to help Syrian refugees. They gave no details about where President Assad would settle if he stepped down.

In Syria, activists say security forces attacked rebels in the capital, Damascus, with helicopters and tanks, while rebels launched an offensive against the government in Aleppo, Syria's largest city.

The activists say government troops used helicopter- and tank fire to try to drive rebels out of the Damascus neighborhoods. Syrian state news agency SANA denied that helicopters were deployed. It insisted the capital was normal and said security forces chased what it called “terrorist” remnants from the streets.

Iraqi officials say Syrian forces have retaken control of one of two border crossings that the rebels seized last week, while Turkey says rebels took over another border crossing with Syria on Sunday.

Aleppo had been largely untouched by the 16-month uprising against President Assad. It is home to Syrian elites and merchants who have benefited from his authoritarian rule.