Israel ignored mounting international calls for a cease-fire Monday and said it won't stop its crippling 10-day assault until "peace and tranquility" are achieved in southern Israeli towns in the line of Palestinian rocket fire.

Israeli forces seized control of high-rise buildings and attacked smuggling tunnels and several mosques in a relentless campaign against Hamas militants that took an increasing toll on civilians. The United Nations said at least 500 people have died in the Gaza fighting,