Gaza City ( CNN ) -- Violence erupted in and around Gaza on Saturday , as Hamas security forces roughed up demonstrators and journalists , and five people were wounded in cross-border fighting . Security forces stormed the offices of international news organizations after the violent break-up of a small demonstration in Gaza City on Saturday , witnesses said . Journalists covering that event were roughed up , they said . They raided the offices of CNN , Reuters and Japanese broadcaster NHK , all in the same building where international news operations are located . Reuters bureau chief for Israel and the Palestinian territories , Crispian Balmer , said one employee was beaten with an iron rod and another was threatened with being thrown out the window . He said a camera was confiscated but was later returned . A TV and a computer keyboard were destroyed by the security forces . The forces forcibly entered the CNN office , demanding to see whether there was any television equipment and asking if anyone had been shooting video footage from the office . NHK Jerusalem bureau chief Disuke Iijima said videotape had been confiscated . No one was hurt at CNN and NHK . After the incidents , Gaza-based journalists , many of whom work for international news organizations , staged a sit-in in Gaza City to protest the government 's tactics and promised a boycott of Hamas press events . The office raids came immediately after uniformed and plain-clothes Hamas security officials broke up a small student rally calling for political unity between the two major Palestinian political parties , Hamas and Fatah . The split developed after clashes between Hamas and Fatah in 2007 that led to Hamas seizing control in Gaza , and Fatah maintaining control of the West Bank . It was the second time in a week that Hamas has cracked down on media covering street demonstrations inside the coastal enclave . On Tuesday , thousands of demonstrators took to the streets calling for political reconciliation . According to witnesses , security forces beat up and detained several protesters and journalists covering the rally . The Tel Aviv-based Foreign Press Association released a statement expressing its `` grave concern '' that Hamas security forces `` brutally attacked photographers and cameramen , beating them , breaking equipment and confiscating photos and video footage . '' The organization called the developments the latest in `` string of of chilling attacks on reporters in Gaza . '' Meanwhile , the cross-border violence between Israel and Gaza led to five injuries . Israeli air raids in Gaza on Saturday badly wounded three children , a hospital official in Gaza City said . But the Israel Defense Forces said it launched strikes after dozens of mortar shells were fired from Gaza into southern Israel . The IDF said troops fired tank shells and helicopters backed forces on the ground . It had no comment on the three injured people , one of whom is in critical condition . But the IDF said two Israeli civilians received minor injuries . Israel said three mortars landed in the regional council of Shalom and two in the regional council of Eshkol . Israel said it wo n't allow Israel 's southern communities to `` continue living under constant threat '' and it holds Hamas , the Palestinian movement that governs Gaza , `` responsible for any terrorist activity emanating from the Gaza Strip . '' Constant rocket fire into southern Israel by Palestinian militants prompted Israel to launch its three-week offensive against in Gaza from late 2008 into January 2009 .
NEW : Foreign Press Association security breaks up demo , raids offices . Two children were wounded in Tel Aviv . Three Israeli were injured during rocket fire .