Gaza City (CNN) -- Israeli jets launched eight air strikes early Friday on Gaza, Palestinian officials said. There were no immediate reports of casualties.
The Israel Defense Forces said in a statement that two weapons factories were hit, one in northern Gaza and the other in central Gaza, as were two weapons depots in southern Gaza.
The strikes were carried out in retaliation against the recent firing of makeshift Qassam rockets from Gaza into Israel, an IDF spokesman said.
"The IDF will not tolerate any attempt to harm the citizens of Israel and will continue to operate firmly against anyone who uses terror against it," the IDF statement said.
"The IDF holds Hamas as solely responsible for maintaining peace and quiet in the Gaza Strip."
On Thursday, Israel dropped leaflets over Gaza warning residents of a possible strike.
The Israeli newspaper Haaretz, citing the IDF, said the strikes were Israeli's initial response to an operation in Khan Younis that killed two Israeli soldiers and wounded two others.
Three of Friday's strikes occurred in Khan Younis, one occurred east of Rafah, one on a cheese factory in Gaza City and one northwest of Beit Lahia, which is northwest of Gaza, Palestinian officials said.
Other strikes were on the Maghazi refugee camp in central Gaza, on a resistance training camp and on a Hamas outpost, they said.
Journalist Talal Abu-Rahmeh contributed to this report.