Israeli aircraft blasted suspected Palestinian weapons facilities and other targets throughout the Gaza Strip on Sunday, at the launch of what the military said would be a "prolonged" offensive against Hamas militants who bombarded Israeli towns with rockets.
The offensive dashed hopes that Israel's recently completed Gaza withdrawal would help restart peace talks and left a seven-month-old cease-fire on the brink of collapse.
The fighting also raised already intense pressure on Palestinian leader Mahmoud Abbas to confront militants, and weakened Israeli Prime Minister Ariel Sharon as he parries a challenge to his leadership.
In a further sign the truce was unraveling, the military arrested 207 Palestinian wanted men in the West Bank overnight, most of them members of the Hamas and Islamic Jihad movements. The military has conducted sweeping arrests of Islamic Jihad militants since the February cease-fire, but this is the first time it has detained large numbers of Hamas members.
Among those arrested were Hassan Yousef and Mohammed Ghazal, two of the most prominent Hamas leaders in the West Bank, Hamas officials said.
A group of senior Israeli Cabinet officials, led by Prime Minister Ariel Sharon, approved the military operation in Gaza at an emergency meeting late Saturday after Hamas militants fired nearly 40 rockets from Gaza at southern Israeli towns.
The rocket barrage, which slightly wounded six Israelis, was the Islamic group's first major attack since Israel concluded its Gaza pullout two weeks ago, AP reports.