16: 50 Four soldiers were injured on the Gaza border Saturday afternoon when an explosive device was set off near their jeep. An IDF spokesman said a tank had returned fire at a Palestinian observation post in response to the incident. According to unconfirmed reports, two of the soldiers suffered severe injuries.

18:45 Two IDF soldiers sustained serious injuries when an explosive device was operated against an IDF patrol along the southern Gaza Strip,  and another two soldiers suffered moderate and light injuries the IDF said in a statement.

19:00 The Palestinian news agency WAFA said Israeli artillery had destroyed a target east of Khan Younes, in the southern Gaza Strip. There were no casualties in the strike, according to the report.

19:30 An initial debriefing of the incident revealed that the soldiers were injured as they conducted a search for explosive devices. The two seriously injured soldiers were from the IDF bomb disposal unit.

19:47 Speaking from Germany where he is attending the Munich Security Conference, Prime Minister Binyamin Netanyahu described today’s incident in the Gaza Strip as “grave” and said “Israel would respond appropriately.”

21:36 According to the Palestinian WAFA news agency,  IAF jets struck multiple targets across the Gaza Strip. WAFA claimed missiles were fired at three locations east of Gaza city.

21:38 Sirens sounded at a number of communities in the Eshkol Regional Council in the Western Negev 

21:53 Sirens sound in the Sha’ar Hanegev Regional Council in the northwestern Negev.

22:00 “IDF fighter planes struck Hamas terrorist targets in the Gaza Strip in response to the terrorist incident earlier today,” an IDF spokesman said in a statement. “A number of terrorist targets were attacked: Among them. An attack tunnel under construction by the Hamas terrorist organization from the Zeitoun neighborhood of Gaza City toward Israeli territory, a military compound in the Netzarim region belonging to Hamas and housing military installations, including weapons production sites, a Hamas military compound in the Khan Younes region. In total, the IDF attacked six targets belonging to Hamas.”

Referring to the attack on an IDF patrol on Saturday afternoon, in which Palestinians are believed to have used demonstration on Friday to plant an explosive device, the statement read: “The IDF sees with gravity attempts by Hamas to use supposedly spontaneous popular demonstrations to turn the border region into an arena of conflict and to execute terrorist operations.”

The IDF also warned Hamas that it is “responsible for the event and its consequences and for everything that occurs in the Gaza Strip above and below ground.”

22:20 A mortar landed near to a house in a kibbutz in the Sh’ar Hanegev region.

22:24 A security source told TPS that the sirens that sounded in the Eshkol region were most likely set off by machine gun fire toward Israeli jets and helicopters flying over the Gaza Strip. Earlier, the IDF said the sires in the Eshkol region were a false alarm. Hamas claims it fired anti-aircraft fire at Israeli jets.

22:45 A rocket hit a house in the Sha’ar Hanegev region, but did not explode.

23:04 An IDF tank opened fire after four Palestinians were spotted trying to cross the border fence near Rafah in the southern Gaza Strip. Palestinian sources report casualties in the incident.

This is a developing story; TPS will provide more details as they become available.