The operation started on Sunday after mechanized sensors were activated to identify tunnel locations and mark them for destruction.
The Palestinian population of Gaza, under an Israeli siege since 2007, uses the tunnels as a lifeline to acquire basic living supplies and fuel to the besieged coastal strip.
Egyptian officials say three major underground supply routes have been found and one of them has been destroyed. Witnesses say the military used stones and concrete to fill the tunnels.
Cairo claims the measure is part of a campaign to restore order in the Sinai desert, without elaborating on the linkage between the two.
The blockade has had a disastrous impact on the humanitarian and economic situation in the impoverished territory.
Some 1.5 million people are being denied their basic rights, including the freedom of movement and their rights to appropriate living conditions, work, health and education.
A humanitarian aid convoy, Gaza Freedom Flotilla, that was heading to the coastal strip on May 31, 2010, came under a military attack by Israeli navy commandos in international waters. Nine Turkish nationals were killed on the Mavi Marmara, one of the six vessels of the convoy.
(www.presstv.ir / 05.09.2011)