Gaza City: Israeli forces and Hamas fighters have clashed directly for the first time since a devastating 2014 war, the Israeli army said Thursday, as a new cross-border tunnel used by the militants was discovered.
Army spokesman Peter Lerner said in the last 24 hours "we have had at least six incidents where Hamas has fired at IDF activities," referring to the Israeli Defence Forces.
He said that Israel had responded in what was the first direct confrontation between Israeli soldiers and Hamas fighters since the last major hostilities in Gaza ended in 2014.
Clashes between Palestinian fighters and IDF forces were continuing east of Rafah in the southern Gaza Strip Thursday afternoon, security sources and witnesses said.
Israel`s military said on Twitter that its forces had "responded with tank fire" to mortars fired from the Palestinian enclave.
The flare-up has raised concerns over the fate of a ceasefire between Israel and Hamas that has held since the 50-day war left more than 2,251 Palestinians and 73 Israelis dead.
Hamas`s armed wing, the Ezzedine al-Qassam Brigades, accused Israeli forces of encroaching into Gazan territory and said it was ready to respond.
"We will not permit this aggression to continue," the group said.
Overnight Israeli air strikes hit four targets in Gaza, wounding four people, three of them children, medical and security sources said.
The Israeli army said strikes targeted suspected tunnels under the border, like those whose destruction it cited as one of the main achievements of the 2014 conflict.
The army announced a new tunnel was found on Thursday, after a first one was discovered in mid-April."Overnight, in response to the ongoing attacks against Israeli forces, an Israel Air Force aircraft targeted four Hamas terrorist infrastructure sites in the northern Gaza Strip," the military said in a statement.
It gave no word on casualties but medical sources in Gaza said a raid on the Al-Zeitoun district wounded four members of the same family -- three children and a 65-year-old man.
The raid hit a garage, its owner Hasan Hasaneen told AFP, saying the vehicles that caught fire were not used by security forces but only for "reconstruction works".
Lerner said the new tunnel discovered on Thursday had been about 30 metres (100 feet) deep.
He did not say how far into Israel the tunnel stretched or when it was built, but confirmed the discovery was made by Israeli forces on the Gazan side of the border.
Israeli media have reported a major technological advance in Israel`s ability to detect Hamas tunnels, with Prime Minister Benjamin Netanyahu last month hailing the "breakthrough in the ability to locate tunnels".
The army has kept the nature of the alleged technology secret and Lerner refused to elaborate.
The army also established a closed military zone around the small Israeli border town of Nahal Oz, saying troops had been fired on in the area.
Gaza has been devastated by three conflicts between Israel and its Hamas rulers and other Palestinian factions since 2008, and reconstruction has been painstakingly slow amid an Israeli blockade on all imports that could have military purposes.Although renewed violence has raised fears of a fresh conflict, sources on both sides downplayed the danger.
"Israel has no interest in escalation whatsoever," Lerner said.
Mustafa al-Sawaaf, former editor at the Hamas-affiliated Palestine newspaper, also stressed that the Islamist movement was not looking for a wider conflict.
"What happened are feelers and will not lead in the near future to a showdown between the resistance and the occupation," he said, saying Hamas was sending a message to Israel to stop its incursions.
"I think the message has been delivered."
The border region has remained relatively quiet since 2014, despite allegations by the army that Hamas is building new tunnels from the enclave that could reach into Israel.
Most of the sporadic rocket fire from Gaza has been attributed to fringe Islamist groups challenging Hamas`s authority, although Israel holds Hamas responsible for all fire from the territory and routinely responds with attacks on its positions.
The UN special coordinator for the Middle East peace process, Nickolay Mladenov, said on Wednesday he was "concerned" about the flare-up.
"It is critical that peace be maintained to ensure the safety and security of Israelis and Palestinians alike," he said.