JERUSALEM - Israeli troops and tanks invaded the Hamas-ruled Gaza Strip late yesterday after eight days of punishing airstrikes failed to halt the militant Palestinian group's rocket fire into Israel.
Gunbattles could be heard from Gaza City as artillery rounds lighted the night sky. Columns of tanks and infantry, backed by helicopter gunships, pushed nearly half a mile into the territory from three directions.
Israeli officials said that they expected a lengthy battle but that they did not intend to occupy Gaza.
"This will not be easy, and it will not be short," Israeli Defense Minister Ehud Barak said.
Hamas issued a defiant statement, saying Gaza would "become a graveyard" for Israeli soldiers.
Army ambulances were seen bringing Israeli wounded to a hospital in the southern Israeli city of Beersheba. The military said a total of 30 soldiers were injured in the opening hours of the offensive along with "dozens" of militants.
Gaza residents said troops were seen before dawn today in the town of Beit Lahiya, north of Gaza City, and the sound of intense fighting could be heard just east of the city, toward the border with Israel.
In the city itself, the Hamas-run Al Aqsa radio station was in flames from a missile strike. Staff had evacuated the building about a week earlier, at the start of the Israeli offensive, and continued broadcasting from another location.
The ground offensive, involving thousands of soldiers, was aimed primarily at Hamas rocket-launching facilities, Israeli officials said. Some of those sites are in open fields, but many are hidden across Gaza in densely populated areas and are difficult to pinpoint from the air.
In choosing to strike from the ground as well as the air, Israel undertook two risks: Its army could get bogged down, surrounded in a messy fight with a paramilitary foe, and Palestinian civilian casualties could rise sharply, raising international pressure on Israel to halt the operation.
Israel's airstrikes have already taken a heavy civilian toll. A missile demolished part of a mosque yesterday in Beit Lahiya during late afternoon prayers, killing 13 people and wounding 33 others inside, a Palestinian medical official reported. Two of the dead were children, he said.
The airstrikes began Dec. 27, a week after Hamas let an Egypt-brokered truce lapse. The six-month cease-fire had begun to break down in November.
