Israeli troops have clashed with Hamas militants on the Gaza border, with reports of some heavy fighting inside Israeli territory.
The military wing of Hamas, the Ezzedine al Qassam Brigades, said some of its fighters were "behind enemy lines" and were involved in gun battles with the Israeli Defence Forces (IDF) near the Gaza border fence.
In a statement, it said: "The Qassam Brigades carried out an operation behind enemy lines.
"Heavy fighting is ongoing with the forces of the occupation."
Israeli soldiers were injured during firefights in the north of the Gaza Strip and security alerts were issued on parts of Highway Four in southern Israel on Saturday, according to Ynetnews.
A statement from the ISraeli military said two soldiers were treated in hospital.
"Earlier today, terrorists attempted to execute an attack against Israelis. The attack was foiled by an IDF force," it said.
"Several terrorists infiltrated into Israel from the central Gaza Strip through a tunnel.
Israeli airstrikes in Gaza have continued into a 12th day "They were aiming to carry out a lethal attack in one of the nearby communities when they came upon an IDF force patrolling the vicinity."
On Saturday, the Israeli military said troops discovered 13 tunnels into Israel in the first 24 hours of its ground operation in Gaza.
It also said it has hit 2,350 targets in Gaza, including 1,100 rocket launchers, in 12 days of fighting.
Engineers are concentrating on a 1.5-mile buffer zone and are looking to destroy tunnels dug since the last major fighting in 2012.
Spokesman Lieutenant Colonel Peter Lerner said: "We have struck hard on the two main strategic assets of Hamas: the rockets and these tunnels."
Ashraf al Kidra, Gaza Health Ministry spokesman, said airstrikes on Friday night raised the death toll in the offensive to more than 310 Palestinians.
One Israeli soldier and one civilian have also been killed over the past 12 days.
Israel began the ground operation on Thursday after rockets were fired into Israel. It has said the offensive could last for up to two weeks.
Meanwhile, French Foreign Minister Laurent Fabius called for an "urgent" truce and renewed support for the Egyptian truce proposal.
The proposal was previously rejected by Hamas.
UN Secretary General Ban Ki-moon is due to leave for the Middle East later on Saturday to help mediate in the Gaza conflict.
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