Israel alleges that Hizbullah militants in Lebanon have rearmed with new long-range rockets capable of hitting Tel Aviv and tripled their arsenal of land-to-sea missiles since last summer's war, the United Nations secretary-general said in a report Wednesday.

Ban Ki-Moon said the reports of Hizbullah's rearming are a cause of great concern for the stability of Lebanon.

"Israel has stated that the nature and number of weapons in Hizbullah's control constitutes a strategic threat to its security and the safety of its citizens," he said.

Israel claims Hizbullah's long-range rocket force is stationed in areas north of the Litani River and that most of the new rockets, including hundreds of Zilzal and Fajr generation rockets, have a range of 155 miles, "enabling them to reach Tel Aviv and points further south," the report said.

"Israel also claims that Hizbullah has tripled its shore-to-sea C-802 missiles and have established an air defense unit armed with ground-to-air missiles," Ban said.

While Israel has not provided the United Nations with specific intelligence due to the sensitivity of the sources, Ban said several speeches by Hizbullah's leader Hassan Nasrallah in the past few months "seem to confirm these Israeli claims."

'Israel undermining UN's credibility'

Senior Hizbullah officials have said Nasrallah's comments were made to serve as a deterrent to aggression rather than as threats to Israel, Ban said.

"Reports of rearming are a cause of great concern which pose serious challenges for the sovereignty, stability and independence of Lebanon," he added.

Ban said Israel's contention that Hizbullah has rearmed to a level higher than before last year's war — and that arms continue to be smuggled across the Lebanon-Syria border despite Syrian denials — raise serious concerns about implementation of the UN resolution that ended the 34-day war between Israel and Hizbullah.

Under the Security Council resolution, weapons transfers to the Iranian- and Syrian-backed militants are banned. Ban warned during a visit to Lebanon in March that arms smuggling threatened the Aug. 14, 2006 cease-fire. The resolution calls for the disarming of all militias.

Ban said there has been no progress the disarmament of Hizbullah and other militias, although he sees this as essential to fully restoring government authority throughout the country. The current political crisis in Lebanon has hindered efforts to implement the resolution.

Ban has said the Shebaa Farms, captured by Israel during the 1967 war, "remains a key issue" in implementing the 2006 resolution. The United Nations determined that the area is Syrian. But Lebanon claims Shebaa Farms — a claim backed by Syria — and Hizbullah continues to fight over the disputed land, arguing that Israel's occupation justifies its resistance.

The report for the first time publishes the provisional "definition" of the Shebaa Farms area, which was prepared by a senior UN cartographer.

Ban said he is encouraged by the Lebanese government's first strides to enhance the control of its borders. He again urged Syria to demarcate its border with Lebanon and establish formal diplomatic relations with its neighbor.

He criticized Israel for failing to provide Lebanon with "the exact location, quantity and type of cluster munitions utilized during last summer's conflict" which has led to an increasing number of deaths and injuries of Lebanese civilians.

"Israel's continued violations of Lebanese airspace not only constitute repeated violations of Security Council resolutions but also undermine the credibility of the UN ... and damage efforts to reduce tension, build confidence and stabilize the situation in southern Lebanon," Ban said.