A day after two Grad-type rockets were fired at the Netivot area, two mortar shells were hit open areas in southern Israel on Friday evening. There were no reports of casualties or damage in both attacks. One of the projectiles landed near the Kerem Shalom border crossing at the southeastern end of the Gaza Strip and the other hit an open area in the Sdot Negev region, and has not yet been located. Earlier Friday, the Aksa Martyrs Brigades claimed responsibility for firing two Grad-type rockets at the Netivot area from Gaza on Thursday night. The Fatah-liked organization said the attack was carried out in revenge for the deaths of three of its members who were killed by the IDF in Nablus last week. The three were gunned down after carrying out a terror attack in Shavei Shomron that killed Rabbi Meir Chai. There were no casualties or damage in Thursday night's attack, but a woman living nearby was treated for shock. Residents of Netivot complained that the Color Red early-warning alarm did not go off. The IDF said the system was not switched on because of concerns over false alarms. The missile strike was the first in the area since March. Ron Stern, who is a member of the Netivot city council, said he was in the shower when he heard the explosion. "It was a complete surprise," said Stern. He understood immediately that a rocket had fallen even though there was no warning siren. "We remember the noise from another period," said Stern. Immediately he got out of the shower and went to check on his two girls, aged 8 and 5, who were sleeping. He also checked out the state of the safe room in his house in case he would need it. Then he returned to the shower. Stern said he did not fear that a second Operation Cast Lead was about to start. He chalked up Thursday night's missile attack either to the new year or to Hamas's attempt to pressure Israel over a deal to release captive soldier Gilad Schalt. The attack came after a mortar shell was fired from Gaza late on Wednesday, the first in two weeks. The mortar hit the Eshkol region. No one was wounded and no damage was reported. In another flare-up, gunmen in the northern Gaza Strip fired at IDF troops on Thursday. No casualties were reported. The Israel Navy returned fire, but could not confirm hitting the assailants. On Wednesday, the Shin Bet (Israel Security Service) released a report saying that 566 rockets were fired at Israel from Gaza in 2009; most were launched in January, during the IDF offensive against Hamas in Gaza. By comparison, 2,048 rockets were fired at Israel from Gaza in 2008. JTA contributed to this report.