A Palestinian fighter from the Izz el-Deen al-Qassam Brigades, the armed wing of the Hamas movement, gestures inside an underground tunnel in Gaza in this August 18, 2014 file photo. REUTERS/Mohammed Salem/Files(reuters_tickers)
JERUSALEM (Reuters) - Israel's military said it had discovered on Thursday a cross-border tunnel built by the Islamist Hamas group from the Gaza Strip, a day after a rare flare-up of violence along the frontier.
The military said Wednesday's violence, in which Hamas militants fired mortar bombs at Israeli forces, may have been an attempt by the Islamist group to prevent the tunnel's discovery. Israel retaliated with tanks and warplanes.
Israel has stepped up work on technologies for spotting the secret subterranean passages after Hamas tunnel raiders took the military by surprise during a 2014 war in Gaza.
One tunnel was unearthed last month without incident. Nobody was killed in Wednesday's clashes, though they pose a test to the truce that has largely held since the 2014 war.
Lieutenant-Colonel Peter Lerner, an Israeli military spokesman, said the tunnel unearthed on Thursday appeared to be 28 metres (yards) deep and that an investigation was underway to determine whether it was dug before or after the war.
He blamed Hamas for Wednesday's mortar fire against Israeli troops who, he said, had been probing at the time for the tunnel within 100 metres (yards) of the Gazan side of the fence. He described this penetration as routine under an Egyptian-brokered ceasefire but said the Palestinian attack was unprecedented.
Hamas, Gaza's de facto ruler, has not confirmed responsibility for Wednesday's shelling and had no immediate comment on the tunnel announcement.
"We suspect that the ... mortars that were fired at the soldiers at several locations (were) perhaps a result of Hamas identifying that the IDF (Israel Defence Forces) is closing in on its assets," Lerner told foreign journalists.
"If so (Hamas) decided to change its policy and ... for the first time, actually opened fire at our operations on the ground."
Some experts say Israel risks precipitating a new war by searching for tunnels Hamas may be keeping in reserve rather than planning to use for imminent attacks because the guerrillas could choose to strike before losing their strategic assets.
Heavily outgunned, Hamas had long looked to its rockets for some parity. But the arsenal was depleted during the 2014 war and by an Egyptian crackdown on smuggling to Gaza.
More than 2,100 Palestinians, mostly civilians, were killed during the 2014 Gaza conflict. Sixty-seven Israeli soldiers and six civilians in Israel were killed by rockets and attacks by Hamas and other militant groups.
Lerner said Israel did not want any escalation of conflict but would do whatever was needed to ensure its security.
"We are prepared to operate in order to prevent these tunnels entering into Israeli territory, even if it means we have to continue operating on the far side (of the border)."
(Writing by Dan Williams; Editing by Jeffrey Heller and Gareth Jones)