JERUSALEM (CNN) -- Israel Defense Forces carried out two airstrikes on an old Hamas Interior Ministry building in Gaza City on Friday, killing one Palestinian woman and injuring 14 people, Palestinian security sources said.
Two of the 14 were critically injured, doctors in Gaza said. Earlier, Palestinian security forces reported that more than 60 were injured in the airstrikes.
The building, located in a residential area, was no longer being used, they said.
An IDF spokeswoman said two airstrikes were carried out, one aimed at a Hamas post in central Gaza and the other at a Hamas base in northern Gaza. She would not say if the former Interior Ministry building was one of the targets.
Aryeh Mekel, a spokesman for the Israeli Foreign Ministry, said the airstrikes were in response to rockets Hamas and other militant groups have fired into southern Israel.
Friday's attack on a large building was unusual; IDF airstrikes in Gaza typically target automobiles or small structures.
Israel "will put an end to the rockets being fired" and take "whatever measures are necessary," he said, adding, "Today was one of those measures."
Militants have fired about 190 rockets and mortar shells into Israel this week, IDF said, and the Israeli army has retaliated with military strikes that have killed at least two dozen Palestinians.
Victims of the Israeli strikes included a senior extremist leader, Israel said, and several civilians, Palestinian security sources said.
Earlier Friday, Israeli Defense Minister Ehud Barak ordered troops to close border crossings that lead to and from Gaza, a spokesman said.
The closure will block the entry of food, fuel and medicine, but Palestinians who need medical treatment will be allowed to cross, a spokesman for Israel's defense minister told CNN.
The military will re-evaluate the closure in a few days, the spokesman said.
Israeli Prime Minister Ehud Olmert said Thursday that Israel would continue its campaign against militants in Gaza. He said Israel has "no desire to harm the residents of the Gaza Strip" but would fight extremists in Gaza "without compromise and without pity."
In the West Bank, meanwhile, Israeli forces killed a Palestinian militant wanted for planning and staging suicide attacks, the Israel Defense Forces said in a statement.
IDF troops and Israel's Security Service personnel raided the Balata refugee camp in Nablus "to arrest a number of wanted militants."
Forces surrounded a house, identified militant Ahmad Muhammad Ibrahim Sanakra, who was holding a Kalashnikov rifle, and shot him dead.
Sanakra was on Israel's most wanted list for involvement in planning and carrying out many suicide attacks, recruiting suicide bombers and preparing the suicide belts. In November 2006, he was wounded while trying to activate a car bomb near Israeli troops.
Four militants -- all from the Al Aqsa Martyrs Brigades, a military offshoot of the Fatah movement -- were arrested. E-mail to a friend
CNN's Kevin Flower and Michal Zippori contributed to this report.