Two explosive devices were detonated close to an army patrol along the border fence with the northern Gaza Strip on Thursday, prompting IDF retaliation against Hamas and Islamic Jihad positions.No IDF soldiers were wounded in the explosions, which took place inside the Hamas-run coastal enclave. Contradictory reports out of Gaza and in Palestinian media said two Palestinians were killed in the five retaliatory strikes that were carried out by tanks and one air strike.Palestinian media reported that Hamas observation sites near Gaza City and Beit Hanun in the northern Strip were struck by Israel. A video uploaded on social media showed the moment when the target in Beit Hanun was hit.IDF Spokesman Brig.-Gen. Ronen Manelis called the incident “serious” and said security forces were also investigating whether an anti-tank missile was fired at troops who were an estimated 100 meters away from the explosions.“We view Hamas as the sovereign power in the Gaza Strip and hold it responsible for everything that happens there,” Manelis said. “We will act decisively against any attempt to turn the [area near] the fence into a hideout for terrorist activities, and we will not allow the demonstrations [by Palestinian protesters near the fence] to turn into terrorist activities.”This was the second time in one month that improvised explosive devices, or IEDs, were targeted at Israeli troops and have been detonated along the Gaza border fence.In February, an IED hidden inside a flag pole exploded along the fence in the southern Strip near Kibbutz Ein Hashlosha. It exploded after protests were held in the area as troops were coming to investigate the suspicious structure on the Palestinian side of the fence.Two soldiers were seriously wounded in that explosion and two others were moderately and lightly wounded.Tension has increased on the Gaza border in recent months as IEDs have been discovered and detonated.In late December, according to Ynet, a powerful IED was neutralized by sappers who used a laser before the device could be detonated. In that incident, two Palestinians dressed in civilian clothes were spotted in a horse-drawn wagon as they approached the border fence and placed the bomb some 20 to 30 meters from the fence.The lasers heated up the IED, causing it to explode and send hundreds of shrapnel pieces flying into Israeli territory. It is still unclear who planted the bomb.The two other IEDs were discovered in March of last year and were neutralized after being found in a closed military zone near the northern Gaza Strip. The devices were then taken for further examination. No one was injured in those incidents.It is assumed that the IEDs that exploded on Thursday morning were also planted during the weekly protests as hundreds of Gazans demonstrated along the border between the Gaza City neighborhood of Shejaia and Kibbutz Nahal Oz. According to the army, protests have grown increasingly violent in recent weeks, with protesters bringing firearms and grenades to use against IDF troops on the other side of the fence.“These spontaneous demonstrations are also used for terrorist activity, and these events will be met with an uncompromising response,” Manelis warned.Last week, Israel used an unmanned aerial vehicle to drop tear gas on protesters. This was reportedly the first time Israel has used a drone in that way.