Israel won't carry out a large-scale military operation in Gaza at this time, Prime Minister Ehud Olmert said Saturday, despite warnings by security officials of a Hamas arms buildup. Israeli security officials fear that Hamas is trying to copy the tactics of the Lebanese guerrilla group Hizbullah which fought Israel to a draw in last summer's war in Lebanon. An Israeli military official said Saturday that Hamas has exploited a period of relative calm to smuggle large numbers of anti-tank missiles and 30 tons of weapons-grade explosives into Gaza, using tunnels under the border with Egypt. Hamas has almost doubled its number of fighters to 10,000 fighters, the security officials said. Hamas dismissed the claims as Israeli propaganda. The Hamas force has 5,500 members, a spokesman of the group, Islam Shahwan, said Saturday. Earlier this month, the group formed a coalition with the Fatah movement PA Chairman Mahmoud Abbas. The new government said it's ready to consolidate a four-month-old truce, but has stopped short of renouncing violence. In the interview broadcast Saturday, Olmert was asked whether a large-scale Israeli invasion of Gaza is needed to halt an arms buildup in Gaza. In an interview broadcast Saturday, Prime Minister Olmert was asked whether a large-scale Israeli invasion of Gaza is needed to halt the arms buildup. "The question is if it has to be a military operation, if it has to be a military operation by us and if it has to be now," Olmert said. "We won't shy away from a military operation if we reach the conclusion, after a thorough check, that it is possible, based on logic and level-headedness and no exaggerations, that there is no better way than this." Asked whether this was the case now, he said: "This is not the case." Analysts said diplomatic constraints might keep Olmert from ordering a Gaza invasion at this time. The US is trying to revive Mideast peacemaking by winning greater involvement of moderate Arab states, and a large-scale Israeli military operation could sabotage such efforts. Also, Olmert is still fighting off criticism that he embarked on the war against Hizbullah hastily, without consultations. He might also be concerned about getting entangled in fighting in crowded Gaza; previous operations have caused many casualties, including among Palestinian civilians, drawing international condemnation but yielding few achievements for Israel. Still, senior military commanders have repeatedly expressed concern about the arms buildup. Last month, Israel's southern commander, Maj. Gen. Yoav Galant, warned that Iran is helping Hamas upgrade its fighting strength by providing technology, funding, and direct military training. Galant said at the time that the training and technology has enabled Hamas to grow from a ragtag militia into a well-organized group resembling an army - complete with battalions, companies, platoons and special forces for surveillance, snipers, and explosive experts. Also, the head of Israel's Shin Bet internal security agency, Yuval Diskin, said that dozens of Hamas operatives are going to Iran for training. He gave no proof for the allegation. Seperately, Olmert also addressed his much publicized spat with Israel's state comptroller, Micha Lindenstraus during an interview with Israel TV's Channel 2. The embattled prime minister said he felt hounded by a "platoon of investigators" in corruption probes, including those ordered up by the main government watchdog. Last month, the comptroller had planned to release an interim report that was expected to accuse the army and Olmert of leaving Israeli civilians virtually defenseless during last summer's Lebanon war, in which Hizbullah guerrillas fired a barrage of rockets and missiles at northern Israel. A total of 39 Israelis were killed when 4,000 Hizbullah rockets fell on the area. The report was delayed after officials in Olmert's office and the army complained that the comptroller was on a witch hunt and had not given them time to answer his questions. Olmert's popularity plunged after the war - which Israelis viewed as inconclusive - and his approval rating has plummeted below 20 percent. Olmert related to two corruption investigations against him: one looking into allegations that he bought a home for far below its market value. Police have also opened an investigation into Lindenstraus charges that Olmert favored business associates in his role as finance minister when the government sold its controlling interest in Bank Leumi in 2005. In addition, Olmert's finance minister has been accused of embezzlement and his justice minister was convicted of sexual misconduct for forcibly kissing an employee of Olmert's office. Olmert said he and his associates were being hounded. "I also ask how it happened that during the time that I, an adult, who has been active for 40 years ... suddenly there is someone who sends platoons of investigators to investigate all corners of my life and incessantly heap criticism on me," Olmert said. Olmert said he was referring to Lindenstrous, and accused him of foot-dragging in his investigation of the real estate deal. "Something here is strange, that's all," Olmert said.