According the the Israel Defense Forces, Hizbullah has built bunkers and underground weapons depots in most southern Lebanese villages as it continues building its army, the Associated Press reports.

A memo from the IDF brass to Israeli embassies on Thursday to Israel details the acceleration of Hizbullah's fortification of the volatile border region since the end of the 2006 Lebanon war.

The memo says, "Hezbollah has built as many as 550 bunkers in the southern Lebanon region, holding various weapons. In addition, the organization has built 300 underground facilities and 100 storage units for munitions including rockets, missiles and other weapons."

"Many of these terror centers are located near hospitals, private homes and schools, Hezbollah's way of taking advantage of the civilian population of Lebanon," the memo said, citing Hizbullah's well-established tactic of placing fighters and munitions among civilians - a war crime - in order to create bad press for Israel when civilians become collateral damage in strikes on such targets.

A military spokesman also confirmed a map published by the Washington Post detailing the exact sites of these facilities was supplied by the IDF.

During second Lebanon War, which lasted for 34-days in 2006, Hizbullah used similar tactics. But the current build-up takes the stategy to an all new level as Hizbullah seeks to work out of the reach of UN peacekeepers -- and into heavily populated civilian areas, Israel says.

Current estimates show Hezbollah has an arsenal of 40,000 short- and medium-range rockets stored in towns villages south of the Litani River. Hizbullah has also obtained long-range rockets. In 2006 Hizbullah possessed only 14,000 rockets.

According to the IDF, Hizbullah has 20,000 fighters, more than a third of whom have undergone combat training in Iran, in southern Lebanon.

The war between Israel and Hizbullah destroyed much of Lebanon's major infrastructure and killed more than 1,200 people in Lebanon and 160 Israelis. Most Lebanese civilians killed were collateral damage in strikes against legitimate military targets Hizbullah had placed in their midst.