Reuters reports the Israeli military as saying on Sunday that it had destroyed a cross-border tunnel that ran from Gaza into Israel and Egypt, allegedly dug by the Hamas.
Residents in Gaza said Israeli jets bombed an area east of the southern town of Rafah, by the Egyptian and Israeli borders, late on Saturday night. Israel confirmed the attack immediately after, but gave no details until Sunday.
"We understand this was a terror tunnel because it runs underneath strategic facilities," Israeli military spokesman Colonel Jonathan Conricus said, referring to gas and fuel pipelines, as well as an army position it ran under.
"It could also have served to transfer terrorists from the Gaza strip into Egypt in order to attack Israeli targets from Egypt."
Hamas did not comment.
Conricus said the tunnel destroyed Saturday was dug by key operatives of Hamas and was 1.5 km long (about one mile), penetrating 80 metres (260 feet) under the Kerem Shalom border crossing into Israel and into Egypt.
"It is definitely a possibility that an attack was imminent," Conricus said, but would not elaborate further.
Kerem Shalom, the main passage point for goods entering Gaza, was shut down on Saturday before the Israeli attack.
During the last Gaza war, in 2014, Hamas fighters used dozens of tunnels to blindside Israel's superior forces. The Israeli military said it has destroyed three such tunnels in the past two months, but that it was not seeking escalation.
Israeli Prime Minister Benjamin Netanyahu said the tunnel was a "major terrorism infrastructure belonging to Hamas in the Gaza Strip. "Hamas must understand that we will not allow these attacks to continue and that we will respond with even greater force," he told reporters before boarding a flight to India.
Israel has been constructing a sensor-equipped underground wall along the 60-km (36-mile) Gaza border, aiming to complete the $1.1 billion project by mid-2019.