JERUSALEM — Israel launched a major ground invasion of the Gaza Strip on Saturday night, moving in tanks, infantry and artillery units after eight days of relentless air attacks failed to halt Hamas rocket fire from the narrow coastal territory.
Israeli officials indicated that the incursion would be lengthy but said they have no intention of reoccupying the densely populated strip more than three years after withdrawing their troops and settlements. Less clear is whether Israel intends to use the ground assault to try to topple Hamas, which has been in control of Gaza for the past 18 months.
Hamas officials called on Palestinians to rise up against Israel with suicide attacks and vowed to make Gaza "a graveyard" for Israeli soldiers.
The invasion came under cover of darkness around 8 p.m., after electricity was cut to much of the strip. Teams of soldiers with night-vision goggles advanced on foot, while others traveled in tanks and armored personnel carriers. The only light came from Israeli flares that periodically illuminated the sky, and from the towers of bright orange flame that followed missile strikes, revealing scenes of devastation on the ground.
Preliminary reports from witnesses in the northern part of Gaza indicated that there had been heavy gun battles between soldiers and Hamas fighters. At least seven Palestinians were killed in the fighting, bringing the Palestinian death toll to at least 460, with more than 2,000 wounded, according to Palestinian medical officials. The United Nations has said that about a quarter of those killed before Saturday were civilians.
Three Israeli civilians and a soldier have been killed since the air operation was launched. There was no immediate word that any soldiers had been killed in the ground assault.
"This will not be easy or short. But we are determined," Israeli Defense Minister Ehud Barak said late Saturday.
Tens of thousands of military reservists were called up soon after the invasion was launched.
Mark Regev, spokesman for Prime Minister Ehud Olmert, said the operation would end "when Israel understands that the civilian population in the south of the country will no longer be on the receiving end of Hamas rockets."
But with a little more than a month until Israel holds elections, pressure has been building for the government to use this operation not just to weaken Hamas, but also to try to deal it a death blow.
Hamas and its allies in Gaza fired about 40 rockets into Israel on Saturday, hitting three homes. There were no major injuries.
"Gaza will not be paved with flowers for you, it will be paved with fire and hell," Hamas warned after the invasion.
In just over a week, Israel had attacked about 800 targets in Gaza from the air. Military officials had defined any Hamas-affiliated target as legitimate, and fighter jets had leveled police stations, government offices, homes of Hamas leaders, smugglers' tunnels and mosques that were allegedly being used to store weapons.
In a statement, the military said the invasion marks the second stage of Israel's campaign to destroy Hamas' armed infrastructure. The military said it also planned to take control of some areas used by Hamas to launch rockets. It was unclear how long Israel intended to hold those areas or how deep into Gaza the forces planned to move.
Israel had intensified its air assault earlier in the evening, firing artillery shells for the first time and killing at least 13 people in an attack on a mosque where the Israeli military said weapons were being stored. Also Saturday, an Israeli airstrike killed a senior Hamas commander, the second to die in the operation.
The escalation of the Israeli offensive came as international pressure continued to build on Israel to find a diplomatic solution.
France on Saturday condemned the ground offensive and called on Hamas to stop its rocket fire. The United States has also pushed for a truce but has said that Hamas must stop firing rockets before Israel should be expected to halt its offensive. In his weekly radio address, President Bush blamed Hamas for the violence.
U.N. Secretary General Ban Ki-moon called Olmert and expressed "extreme concern and disappointment," the United Nations said.
Libya introduced a draft press statement that expressed "serious concern" at the Israeli ground offensive and called for an immediate halt to all violence. But a State Department spokesman said the United States would not support a Security Council decision that preserved the "status quo" and allowed the continuation of Palestinian rocket attacks against Israel.
Protests were held worldwide Saturday, with demonstrators calling for Israel to stand down. In Tel Aviv, thousands of people gathered in Rabin Square to demand an end to the operation.