The IDF is prepared if Hizbullah or Palestinian terror groups escalate rocket attacks from Lebanon, senior defense officials said Thursday, after four Katyushas struck Nahariya earlier in the day. Two people were lightly wounded when one of the rockets scored a direct hit on a Nahariya retirement home and exploded in the kitchen as some 25 elderly residents were eating breakfast in the adjacent dining hall. One resident broke a leg and another sustained bruises, both apparently from slipping on the floor after emergency sprinklers came on. "The rocket went through the roof, hurling the water heaters into the air. It went through upstairs bedrooms and then into the kitchen. There was a massive blast," said Henry Carmelli, the home's manager. The rockets were fired from the southern Lebanese town of Nakoura. Late last month, a farmer in Hammoul, northeast of Nakoura, discovered eight Katyusha rockets pointed at Israel, and the Lebanese army diffused them. The IDF's Northern Command held consultations following the attack, saying "Israel holds the government of Lebanon and the Lebanese armed forces responsible for preventing rocket fire into Israel." The army also said that Palestinian elements were interested in "dragging Lebanon into a war." Defense officials said it was possible the rocket attacks from Lebanon would continue as the IDF operations in the Gaza Strip intensified. Thursday's attack did not come as a surprise to the IDF, which raised its level of alert in the North after launching Operation Cast Lead on December 27. "We are closely following what is happening on the northern border and we are ready to respond as necessary," Defense Minister Ehud Barak said Thursday during a tour of the Tze'elim Training Base in the South. Defense officials said it was likely that the salvo was fired by Palestinian terrorists and not by Hizbullah, but that the possibility Hizbullah had instructed another group to fire at Israel could not be ruled out. "Nothing happens in Lebanon without a green light from Hizbullah," a senior defense official told The Jerusalem Post. "Even if it was a Palestinian group who fired the rockets, Hizbullah would have to at least have turned a blind eye to allow the rocket fire." Muhammad Fneish, a Hizbullah minister in Lebanon's cabinet, denied the group was involved, and told The Associated Press that Hizbullah was not aware of the rockets targeting Israel. A Lebanese government official said the country was trying to determine who launched the rockets. In a statement Thursday, Prime Minister Fuad Saniora said Lebanon was committed to UN Security Council Resolution 1701, which ended the Second Lebanon War in 2006. "The firing of rockets is rejected and is the work of parties who stand to lose from the continued stability in Lebanon, and want to drag it to a situation it does not want and which serves the Israeli plan and does not serve Lebanon's interests nor the Palestinian or Arab interests," the Lebanese leader said. An Al-Jazeera reporter with close ties to Hizbullah said there was no chance the rockets were fired by the Shi'ite terrorist group, because they were an outdated model that Hizbullah had not used for years. Channel 10 also quoted him as saying that had Hizbullah wished to open a second front on Israel's North it would have fired dozens of rockets. On Wednesday, Hizbullah leader Hassan Nasrallah stepped up his rhetoric, warning that the IDF could not destroy Hamas and that Israel would suffer another "defeat" should it attack Lebanon. In a speech broadcast on Arab media channels, Nasrallah vowed to crush any offensive Israel might launch against Hizbullah. UNIFIL said in a statement that it had received reassurances from the Israeli and Lebanese governments about their "continued commitment to maintain the cessation of hostilities." UNIFIL also said additional troops had been deployed and patrols intensified across the peacekeepers' area of operations to prevent any further incidents. The Lebanese army also sent reinforcements. AP contributed to this report.