GAZA CITY, Gaza Strip -- Israel seized control of high-rise buildings and attacked houses, mosques and smuggling tunnels as it pressed its offensive against the Gaza Strip's Hamas rulers on Monday, even as a stream of European leaders headed to the region to push for a truce.

At least 10 Palestinian children were killed, raising the known death toll from a new ground invasion to more than 80, a Palestinian health official said. The vast majority of confirmed...