Gaza militants bombarded southern Israel with 20 mortar rounds in the space of an hour midday Tuesday, provoking Israeli ground strikes that killed three militants from the territory's ruling Hamas group. The violence flared in northeast Gaza just as Israel's top leadership was debating whether to pursue a truce with the Islamic Hamas or embark upon a broad military operation against it. There were no Israeli casualties. Since Israel withdrew its troops from Gaza three years ago, militants have been tormenting southern Israel with near-daily rocket and mortar attacks, confounding Israel's high-tech military with their crude weapons. The rocket fire has intensified since the Hamas militant group took control of Gaza last year. Israel has so far limited its military reprisals to pinpoint attacks, fearing a broad military campaign would result in heavy casualties for its troops. But with four Israelis killed in attacks this year, Israel's leadership is under domestic pressure to do something about the assaults on its territory. On Tuesday, Israel's top three officials – Prime Minister Olmert, Defense Minister Barak and Foreign Minister Livni – sat down to discuss what course to take. As they met, Hamas militants launched their mortar barrage. The military said it carried out two ground strikes against the mortar squad after 20 mortars fell on border areas. Hamas said three members of the group's military wing were killed during Israeli strikes. Israel's military action “clearly indicates that Israel is not interested in achieving calm,” Hamas spokesman Abu Zuhri said.