Israeli and Hamas spokesmen on Thursday sought to play down fears of fresh warfare akin to their 50-day conflagration in 2014, which ended with a fragile ceasefire that has largely held for two years.

Hamas official Mousa Abu Marzouk said Egypt and Qatar had intervened in bids to restore calm. Army spokesman Peter Lerner said Israel had "no interest in escalation whatsoever."

Overnight, Israeli aircraft targeted "four Hamas infrastructure sites" in the northern Gaza Strip after troops came under mortar fire, Israel's military said.

Medical sources in Gaza said four members of the same family were wounded - three children and a 65-year-old man - in an airstrike on a workshop in Gaza's Al-Zeitoun district (pictured above).

New tunnel found

Lerner said Hamas had fired at least six times at Israeli troops after they discovered a new Hamas tunnel stretching into Israeli territory at a depth of 30 meters.

"The IDF [Israeli Defense Force] exposed a second tunnel in the southern Gaza Strip," he said, confirming that the find was made by Israeli forces inside Gaza.

No casualties were reported.

Israel had destroyed another tunnel last month, accentuating Israeli concerns that Hamas might be rebuilding its underground network to conduct attacks against Israel.

Lerner speculated Hamas militants had opened fired because they realized that Israel had been closing in the latest tunnel.

"It's something we are not prepared to tolerate," he said.

Last month, Israeli Prime Minister Benjamin Netanyahu hailed a "global breakthrough in the ability to locate tunnels," without disclosing further details.

Reconstruction slow

The 50-day conflict in 2014 left dead more than 2,200 Palestinians, two thirds of them civilians, and on the Israeli side, 66 soldiers and seven civilians.

Toward the end that conflict, Israel destroyed more than 30 tunnels that had been dug under the border.

Reconstruction in Gaza has been slow amid an Israeli blockade on imports deemed applicable for military purposes.

UN envoy urges restraint

On Wednesday, the UN special coordinator for the Middle East peace process, Nickolay Mladenov, said he was "concerned" about the latest flare-up.

"It is critical that peace be maintained to ensure the safety and security of Israelis and Palestinians alike," said Mladenov.

In the West Bank late on Wednesday, Palestinian leaders said they would no longer tolerate Israeli raids into Palestinian cities by "immediately" implementing a March 2015 decision to suspend security cooperation with Israel.

Israel insists that such raids are necessary to foil plans by radicals.

ipj/sms (dpa, AP, AFP)