Jerusalem  - A senior Israeli minister accused Syrian President Bashar al-Assad on Sunday of committing genocide during his crackdown on a 15-month uprising, in an unusually harsh censure of the Jewish state's Arab neighbor.

Vice Prime Minister Shaul Mofaz also criticized Russia for arming Damascus and repeated Israel's demand for international military intervention to topple Assad, akin to last year's campaign in Libya.

Israel has until recently been slow to call for Assad's fall, wary of worsening the turmoil in Syria - the two countries are enemies but have been in a mostly stable stand-off for decades.

With hourly media reports in Israel of Syrian civilian deaths, public anger has been growing and Israeli officials have been stepping up their criticism.

"A crime against humanity, genocide, is being conducted in Syria today. And the silence of the world powers is contrary to all human logic," said Mofaz during an interview on Israel's Army Radio.

Foreign powers were "making do with flaccid condemnation" rather than intervening to overthrow Assad, he added.