Israeli troops, backed by air forces, fanned out across the Gaza Strip Saturday night following a week-long air campaign that has killed at least 450 Palestinians.

The following are Israel's ground offensives in Gaza since its unilateral pullout from the Gaza Strip 40 months ago.

On September 12, 2005, Israel completed its unilateral withdrawal from the Gaza Strip, ending a 38-year occupation there. But since then, under the excuse of responding to Palestinian militants' attacks, Israel has entered Gaza many times, launching a number of military operations.

On June 28, 2006, Israel started a military operation dubbed "Summer Rains" against Gaza, three days after an Israeli soldier was kidnapped by Palestinian militants during a predawn attack on an Israeli military post near the Gaza border.

During the operation, which lasted more than four months, Israeli troops bombarded the region, and more than 60 Islamic Resistance Movement (Hamas) members, including eight cabinet ministers and 24 lawmakers, were arrested.

On November 1, 2006, Israel began the seven-day Operation Autumn Clouds in northern Gaza in response to Palestinian militants' increasing rocket attacks and failure to reach a deal on prisoners' swap.

The two sides reached a ceasefire on November 26 and Israeli troops pulled out.

More than 400 Palestinians, many of them civilians, were killed during operations Summer Rains and Autumn Clouds.

From FebRURAY 27 to March 3, 2008, Israel launched Operation Hot Winter in Gaza, during which over 120 Palestinians were killed.

(Xinhua News Agency January 4, 2009)