The Israeli military has uncovered another tunnel, the biggest so far, dug from the Hamas-ruled Gaza Strip, stretching into Israel and intended for militant attacks or abducting soldiers and civilians.
According to military spokesman Lieutenant Colonel Peter Lerner, the opening of the "terror tunnel" was hundreds of yards inside Israel.
Israel has found several such tunnels in recent years but this was the biggest found to date, Lt Col Lerner said. He said parts of the tunnel were still uncovered and that there are concerns it could be booby-trapped. He said it was near several Israeli border communities but did not give a more exact location.
Another part of Gaza's border, that which adjoins Egypt, is honeycombed with tunnels used for smuggling.
The tunnel into Israel was found this week by Israeli intelligence and the military, Lt Col Lerner said, saying the structure was lined with concrete and describing it as very sophisticated, resembling a subway tunnel.
"This advanced tunnel was intended to pose a direct link and threat to Israeli territory, and enable Hamas terrorists to reach and harm Israeli civilians," he added.
An electric generator and tools, along with fresh tracks, were found in the tunnel, indicating that it had been worked on recently.
Hamas spokesman Abu Obeida said he blamed the tunnel's discovery on recent rains that exposed its opening, insisting the tunnel itself was old.
"Our mujahedeen (holy warriors) worked to fix it," he said, offering a possible explanation of the fresh tracks. "The enemy's allegations about intelligence efforts behind the discovery are a big lie."
Israel has for years banned cement from entering Gaza, arguing it could be used by militants. But since 2010, it has allowed some construction materials in for internationally-funded construction projects.
Israel and Hamas are bitter enemies. Palestinians have been deeply divided since Hamas overran Gaza in 2007, ousting forces from the Fatah party, led by the Western-backed secular Palestinian president Mahmoud Abbas, in bloody street battles.
Abbas has since ruled only in parts of the West Bank, and the Islamic Hamas has held sway in Gaza. Israel is engaged in peace talks with Abbas while shunning Hamas.
Gaza militants have fired thousands of rockets and mortar rounds at Israel over the past decade. Attacks have declined since an eight-day Israeli offensive in 2012 against Gaza militants aimed at stopping what was almost daily fire at the time. But rocket fire still persists.
Last week, Gaza militants fired the heaviest rocket barrage at Israeli communities since 2012, and Israel responded with air strikes on militant targets.
Earlier this month, Israeli special forces captured a ship in the Red Sea carrying rockets and other weapons that Israel said were supplied by Iran and destined for militants in Gaza.