The Israeli military announced on Saturday an explosive device was detonated near an Israeli army unit near the southern Gaza borders. In response the Israeli forces hit an observation post in Gaza with tank fire.

Palestinian media reported no injuries on their side but stated that three Israeli soldiers were injured during the attack; no Israeli media confirmed the news.

Israeli media said the explosion occurred after a suspicious object was discovered by an Israeli patrol. The object, is said to be a Palestinian flag that might have been placed there during the Friday protests.

The object exploded after attempts to neutralize it, Israeli Channel 10 reported. The Israeli Radio correspondent called the attack “serious and irregular.” Another Israeli media said that the incident might be the biggest since the end of Operation Protective Edge in 2014.

Earlier last month the Israeli air forces destroyed a tunnel under the Egyptian-Palestinian borders. Even though Israel claimed the tunnel was used for smuggling weapons into Gaza, Hamas maintain it was used for smuggling basic goods.