GAZA -- At least 13 hostages captured by Hamas were killed in Israeli airstrikes on Gaza in the past 24 hours, Al-Qassam Brigades, the military wing of Hamas, said Friday.

"Foreigners and Israelis were killed during the intense Israeli attacks in northern Gaza and inside Gaza City during the past 24 hours," it said in a press statement.

Six were killed in the northern Gaza Strip, while seven were killed in separate places in Gaza City, according to the statement.

The Israeli army announced that it attacked about 750 targets Thursday night in the Gaza Strip, including underground tunnels, military compounds and sites, homes of officials, weapons depots, and communication rooms, in addition to eliminating activists.