Shin Bet chief Yuval Diskin warned lawmakers of copycat terrorist attacks in the works three hours before Tuesday afternoon's bulldozer rampage in Jerusalem, which left over a dozen people injured.

In his appearance before the Knesset Foreign Affairs and Defense Committee, Diskin said the Shin Bet received indications that Palestinians were planning to stage attacks mimicing the deadly incidents in Jerusalem, including the first bulldozer attack and the shooting massacre of yeshiva students at Mercaz Harav earlier this year.

"If we do not take care of the power vacuum, Jerusalem will turn into a serious problem," Diskin told the committee when asked about the spate of recent attacks in the capital. The Shin Bet chief called on the government to seal and destroy the terrorists' homes in order to preserve Israel's deterrent capability.

Diskin warned that sections of Jersualem on both sides of the West Bank separation fence have become security vacuums, and that Israel is unable to properly enforce the law in these areas without deploying large numbers of forces. "Today, entering [the East Jerusalem area of] Shuafat requires massing a greater number of forces than it does entering Jenin," Diskin said.

Diskin also warned the Knesset panel that Hamas has been bolstering its military strength in the Gaza Strip, and has developed missiles capable of reaching past the northern Negev town of Kiryat Gat.

Diskin told committee MKs that security forces must demonstrate "field presence" against the growing threat.

He reiterated his opposition to the cease-fire agreement in the Strip and said that Hamas was exploiting the terms of the truce to arm itself and the territory.

The Shin Bet chief pointed to the drop in number of terror attacks in the West Bank, as a result of the security fence and the increased presence of Israeli forces, and said the same tactics must be used in Gaza.

Diskin delivered a similar assessment to ministers in late May.

Palestinians have been firing Qassam rockets and mortar shells at the Negev town of Sderot, some 5 kilometers from the Gaza border, for the past seven years. Recently, however, they have been able to reach Ashkelon, some 12 km away. Diskin's assessment is that they have now doubled their range.

In response to Diskin's warning, committee member MK Limor Livnat told Haaretz: "These words speak like a thousand testimonies to the government's complete failure in defending its citizens."

"A government that does not listen to the head of the Shin Bet and instead focuses on conflicts between the prime minister, the foreign minister and the defense minister needs to go home," she added.