The Israel Navy is preparing to significantly boost security surrounding the country's natural gas rigs in the Mediterranean Sea due to growing threats of attack, local Ha'aretz daily reported on Monday.

The army's high command recently tasked the navy's missile boat flotilla with securing the Tamar, Leviathan and Yam Tethys drilling platforms off the Haifa coast, Ha'aretz said.

The rigs are located some 22 km beyond Israel's territorial waters, but are within the country's "economic waters zone," an area that extends up to 130 km into the Mediterranean.

The plan would deploy the missile boats, which have already held protective training maneuvers in the seas around the rigs, to conduct patrols and secure future drilling platforms.

Israel's defense establishment is increasingly concerned about the dangers posed to the offshore rigs by militant groups or an armed conflict with neighboring states.

Hezbollah Deputy Secretary-General Sheikh Naim Qassem vowed last July that his organization would not allow Israel to encroach on what he said was Lebanon's maritime sovereignty and seize its oil, gas and water resources.

"Lebanon will stand guard in order to protect all its rights, no matter the cost," Lebanese media quoted Qassem as saying.

Lebanon last year contested the demarcation of its maritime border with Israel at the United Nations, but the international body ruled that the platforms were within Israel's zone.

Israeli defense officials have said that Hezbollah might attempt to target the offshore rigs as well as Israeli ports with explosives-laden vessels and anti-ship missiles.

"The threats don't only concern the rigs and those working there, but also Israel's energy supply. A possible strike against the rigs is a nightmare scenario," a senior naval officer told Ha' aretz.

Other naval officers, however, have complained that the new role, which is expected to require allocating thousands of operational hours each year, will come at the expense of other critical missions.

"We'll get more boats for the mission, but that isn't enough. We need even more. One can't strengthen the navy in the long run like this," a senior officer said.

He said plans were underway to purchase two missile boats in the coming years that will join the 10 vessels currently in operation.

The navy isn't alone in protecting the vast gas reserves, which Israel said have a potential to yield billions of dollars in the next decade. In August, the Israel Air Force began deploying surveillance drones over the rigs as an additional layer of protection.