The Israel Air Force struck an Islamic Jihad member in the northern Gaza Strip on Sunday morning who had been involved in a spate of rocket attacks against Israel.Security sources said following the strike that Islamic Jihad, as the non-sovereign party in Gaza, was exploiting its position to attack Israel, and that the coming hours would determine whether Hamas would be able to exercise its authority as Gaza’s ruler to reinstate the truce with Israel.The target of the strike, named as Ahmed Sa’ad, took part in the firing of rockets at southern Israeli communities, the IDF said, and planned further attacks in the near future.Palestinian media sources said a missile struck a 22-year-old motorcyclist in Gaza who sustained serious wounds, along with a 12-year-old boy who suffered moderate wounds.“We acted to remove an immediate threat to Israeli civilians,” the IDF spokesman said.“Sa’ad was personally responsible for the firing of rockets at Ashkelon last Thursday,” he added, referring to an attack that saw five rockets fired at the southern city in the middle of the night, setting off air raid sirens. The Iron Dome anti-rocket system intercepted all of those projectiles.Israel will maintain the quiet in the South by forcefully responding to every rocket attack coming from the Gaza Strip, Prime Minister Binyamin Netanyahu told the cabinet at its weekly meeting Sunday.Speaking soon after the air strike, the prime minister said, “We are determined to preserve the quiet in the South. We do this through a policy of prevention and by responding powerfully against those who try to harm or hurt us. I suggest Hamas take our policy into account.”Sa’ad was also involved in planting rocket launchers, the IDF Spokesman’s Office added.Sa’ad also fired rockets at Israel during Operation Pillar of Defense in November 2012 and an earlier escalation in March 2012, according to the military.He is considered to be a mid-ranking Islamic Jihad operative.According to Palestinian news agency Ma’an, two other Israeli air strikes on sites used to train Palestinian fighters in central and southern Gaza left no reported injuries.The IDF has been on alert in the South since Thursday for the eventuality of a security escalation. The air force, intelligence units and the Operations Branch are prepared for a potential escalation.Security sources said Hamas must enforce the truce arrangement in place since the end of Operation Pillar of Defense, adding that the coming hours will tell whether Hamas understands that fact or not. The attack represents the first preemptive strike by the IDF on a terrorist target in a long period.January has seen an upsurge in Palestinian rocket attacks from Gaza on southern Israel, with 18 projectiles fired since the start of the month. Sunday’s air strike can be seen as a message from the IDF that Israel is prepared to target terrorists personally involved in the attacks.“It’s a signal that we won’t tolerate a drizzle of rockets,” a senior security source said.Defense Minister Moshe Ya’alon said Sunday that Israel will not allow anyone to return it to a “routine” of rocket fire, warning that “those who try to do so will pay a very high price.”“We see Hamas as being responsible for what occurs in the Gaza Strip, and if it does not know how to enforce its sovereignty on what takes place on the ground, we’ll keep hitting its interests,” he added. “I would not recommend that anyone in the Gaza Strip test our patience and determination to protect the security of Israeli civilians.”Earlier on Sunday, the IAF retaliated for Gazan terrorists firing a rocket at Israel on Saturday evening, triggering air raid sirens in the Sdot Negev Regional Council. A number of targets in Gaza were bombed.Lt.-Col. Peter Lerner, an IDF spokesman, said “the sites attacked this evening are part of the terrorist support network, enhancing terror capabilities against Israel and it civilians. As long as Hamas enables its henchmen to attack Israel, these sites will not be immune from our watchful eye and operational strike, while they are used to formulate, train and develop malicious terrorist intentions.”Saturday’s attack comes amid recent tensions on the Gaza border. Early last week, the IDF retaliated for two rockets that hit Israel. The IDF said the targets the IAF hit were a military compound and a terror infrastructure site, adding that both strikes hit their targets accurately.Herb Keinon and Jerusalem Post staff contributed to this report.