A rocket fired from the Gaza Strip exploded between two homes in Sderot on Sunday afternoon.In response, the IDF hit Hamas terrorist infrastructure targets in the northern Gaza Strip with air power and tank fire.The army said that it will “continue to act with determination at all times to guard the security of the citizens of the State of Israel.”The IDF would not identify its targets other than that they were connected to Hamas.However, Palestinian reports indicated that the Israel Air Force attacked a Hamas lookout point and that a tank shell damaged a water tower in Beit Hanun, on the northeast edge of the Strip.There were conflicting reports about whether Gazans were wounded by the IDF’s counter-strikes and how many were injured.Despite targeting Hamas, the IDF declined to identify who was responsible for firing the rockets, but Palestinian reports indicated that it was the Abu Alu Mustafa Brigades, the “military” arm of the Popular Front for the Liberation of Palestine. On Saturday, Jamil Mazhar, a member of the PFLP Politburo, may have hinted that the next day’s rocket attack relates to the ongoing administrative detention and 67-day hunger-strike of PFLP terrorist Bilal Kayed. Mazhar said that the coming days will be decisive, saying the PFLP will not for a moment turn its back on its comrade Kayed and calling on the “occupation,” i.e., Israel, not to test the organization’s patience.“Those who support a ceasefire should take our message seriously, because the occupation will not enjoy peace and security while comrade Bilal Kayed is fighting death for the sake of freedom,” he added.At the same time, a source who spoke to The Jerusalem Post said the Abu Ali Mustafa Brigades were denying responsibility for the attack.Abu Obeida, spokesman for Izzadin Kassam, Hamas’s “military” wing, warned Israel that “the Kassam Brigades and the Palestinian resistance are ready to defend our people at any time and fighting a battle can be forced upon us at any time, we warn the enemy against any guile, deception, adventure or stupidity.”Police confirmed that the Gazan projectile’s impact site had been located in Sderot, a city of some 19,000 residents.Rocket warning sirens sounded prior to the projectile’s strike, and residents in the area reported hearing an explosion.There were no initial reports of injuries or damage. Residents were prohibited from entering the area until police bomb disposal experts concluded their investigation.But there were no instructions for people to stay in their homes as the day went on.Sderot Mayor Alon David said, “Terrorism will not defeat us and will not break our citizens’ fortitude. These have been the quietest two years this area has known and it cannot be that an isolated incident will end the quiet.“We will continue forward, and tonight we will all enjoy the Heart of Sderot Festival,” David said.Former defense minister and current Zionist Union MK Amir Peretz responded to the attack, saying, “I have no intention of challenging the current defense minister and it cannot be that a military operation would be part of a political or personal agenda.”He warned that it was important to strike the right balance in responding with a show of military strength, but without being unintentionally dragged into a broader escalation.Defense Minister Avigdor Liberman made no comment about the day’s events.According to the IDF, 14 rockets from Gaza have been fired into Israel so far in 2016.The last rocket attacks from Gaza were on July 1, when one projectile hit an open area in the Sha’ar Hanegev region and another hit outside a pre-school in Sderot. No one was hurt. The air force carried out strikes against Hamas in that case as well.In late May, Ajnad Bait al-Maqdis, a Salafi terrorist organization operating in the Gaza Strip, claimed responsibility for a rocket strike on southern Israel.In response to rocket fire launched toward Israel on May 25, the air force attacked two Hamas terrorist infrastructure targets in the Gaza Strip.Adam Rasgon, Jerusalem Post Staff and Reuters contributed to this report.