GAZA CITY, Gaza Strip -- Israeli tanks and armored vehicles, backed by helicopters, pressed into the Gaza Strip early Wednesday, firing at houses and prompting hospitals to go on alert for casualties, residents said.
Between 15 and 30 Israeli tanks and armored personnel carriers moved from areas near the Erez crossing with Israel toward Beit Lahiya and the Jabaliya refugee camp north of Gaza City, residents said.
Tanks were firing shells and machines at houses and two helicopters were flying low overhead, searching for suspected militants, Palestinian security officials and residents said.
At least one person was critically injured with a gunshot wound to the head, hospital officials said.
The army said it was checking the report.
Jabaliya is a hotbed of Hamas militants as well as other militias which have carried out attacks on Israelis during the past 22 months of fighting.
The incursion followed three Israeli missile strikes on Monday at a suspected weapons factory in Gaza City. Four people were slightly injured.