Israel froze shipments of building materials to the Gaza Strip on Sunday after the discovery of a tunnel packed with explosives entering its borders, a defense official said.
"Due to security reasons, (the army) decided to stop for now the transfer of building materials into Gaza," Guy Inbar told Agence France Presse.
Inbar, who is also the spokesman for the unit of the Israeli defense ministry responsible for civilian affairs in the Palestinian territories, did not elaborate on the ban or give any indication on how long it would remain in force.
Last month, Israel allowed the delivery of cement and steel for use in the private sector into the Gaza Strip for the first time since 2007, when Israel banned their transfer as part of a larger economic blockade imposed on the Strip at the time.
Israeli officials said on Sunday that a sophisticated tunnel running 450 meters into Israel and intended as a springboard for militant attacks had been uncovered by troops, AFP reported.
"I want to congratulate the army for exposing the Gaza terror tunnel," Israeli Prime Minister Benjamin Netanyahu told the weekly cabinet meeting on Sunday. "It is part of our offensive policy against terror, both in prevention and intelligence, proactive activity, reactive activity."
The army did not immediately publish details of the tunnel, but the head of the Israeli local council where it was found said that he had been taken inside for an inspection.
"This tunnel, which looks like the New York subway, is apparently intended to kidnap soldiers or for some other kind of terrorist attack," Haim Yelin told army radio.
"It is impressively executed, with concrete supports."
Israeli news website Ynet said that the tunnel was equipped with railway tracks and lighting, and quoted chief military spokesman Yoav Mordechai as calling it "one of the most advanced terror tunnels to be uncovered in recent years."
Yelin denied media reports that the tunnel was aimed at attacking an Israeli village or kibbutz or that it was to be used to set off explosives under a kindergarten.
"This tunnel penetrates into the state of Israel 300-400 meters from the border with the Gaza Strip," he said.
"It is situated 2.5 kilometers from any of the kibbutzim and moshavim (collective villages) in the area."
The Gaza Strip has been under a severe economic blockade imposed by the State of Israel since 2007.
The blockade was imposed following the victory of Hamas in the 2006 Palestinian elections and the subsequent 2007 clashes between Fatah and Hamas, which left Hamas in control of the Strip and Fatah in control of the West Bank.
The blockade has severely limited the imports and exports of the Gaza Strip and has led to frequent humanitarian crises and hardship for Gazans.
These have been particularly severe given frequent Israeli military assaults, particularly in 2008-9 and 2011, which killed around 1,400 and 170 Gazans respectively and led to major infrastructural damage.
