Defense officials vowed a tough response Sunday night to a Kassam rocket attack in the afternoon that wounded two people at a gas station near Sderot. A 24-year-old worker at the gas station sustained moderate wounds after his body was hit by shrapnel from the rocket attack. Another bystander was lightly wounded. The rocket, with a sticker reading "Quds" - Jerusalem in Arabic - struck the gas station in Sha'ar Hanegev and caused light damages. The wounded youth was evacuated to Ashkelon's Barzilai Hospital. The IDF said 10 Kassam rockets have been fired at Israel since Friday. Two more were fired Sunday night but landed in open fields. The Islamic Jihad claimed responsibility for the attack and said it was in retaliation to IDF operations in the West Bank. Defense officials estimated that the government would not launch a ground operation inside Gaza in response to the attack, but would order the IDF to step up pinpointed strikes on terrorists and infrastructure involved in the production and operation of Kassam rockets. Earlier in the day, a 42-year-old security guard was seriously wounded after Palestinian terrorists gunned him down at the joint Israeli-Palestinian tank farm where he was employed in the West Bank. The guard was exiting the second-floor balcony where the facility's bathrooms are located when three or four attackers in a passing car opened fire at him. Employees of the facility, which is located not far from Nili, west of Ramallah, said the bathroom area was the one part of the facility exposed to attack. The facility is a transfer point where gasoline from Israel is transferred to PA distributors. Filled with hundreds of gallons of flammable gasoline, the facility is considered to be a potential powder keg. Due to the level of danger, few people are willing to work as security guards at the site. But the worker, a new immigrant, had been employed there for around a year. Witnesses said they saw the car involved in the shooting speed off towards the nearby Palestinian village of Dir Kadis. The IDF later closed the village of Ein Arik, to which they believe the terrorists fled. Coworkers, including one man who had worked for years as an MDA ambulance driver, piled the guard into a car and drove him to the Na'alin checkpoint, where an MDA ambulance waited to rush him to Sheba Hospital at Tel Hashomer Medical Center. Medics said that although the guard was conscious immediately following the attack, his condition deteriorated en route to the hospital. Ultimately, rescuers were forced to resuscitate him before reaching the intensive care unit. Binyamin Police who swept the area for evidence discovered shells near the scene, which they suspected had come from the gun used in the attack. Doctors said the shooting victim remained in extremely serious condition on Sunday night. His condition still had not stabilized, and doctors emphasized that he was still fighting for his life, after losing a leg and an eye, as well as sustaining severe head wounds. At least two of the guard's wounds are each life-threatening on their own, even before taking into consideration the "whole picture" of the additional wounds. The Aksa Martyrs Brigades later claimed responsibility for the shooting. Security forces believe that the same group was responsible for an attack in the area three weeks ago in which four Israelis were wounded. In that case, too, the shooters were members of the group, and the attack was carried out by a car speeding by. Security forces were combing the nearby village and surroundings to search for the cell responsible for the recent attacks. Earlier in the day, Palestinians threw rocks at an Israeli bus near Kalkilya. No one was hurt in that incident, but the bus sustained damage.