Two Palestinians have been killed in Israeli air raids in the Gaza Strip, medics and security sources say. Another person has been critically injured.
The Israeli army launched three raids in the south of Gaza on Saturday after Palestinian fighters fired a rocket over the border.
The flare-up of violence on the Israel-Gaza border came just two days after the relaunch of Israeli-Palestinian peace talks in the US.
Israeli aircraft reportedly struck targets including smuggling tunnels running under the border with Egypt at Rafah.
The two Palestinians were killed when one of the tunnels collapsed. Three others were wounded.
A raid also struck a former base of the Izz al-Din al-Qassam Brigades, the armed wing of Hamas.
An Israeli military spokesman confirmed the three raids, saying one was aimed at "a tunnel dug in the direction of Israeli territory" for attacks across the border.
Early on Saturday, Palestinian fighters fired a rocket from the Gaza Strip into southern Israel, causing no injuries, the Israeli military said.
Gaza is under the control of Hamas, the Palestinian faction which is strongly opposed to negotiations with Israel.
Hamas has vowed to carry out attacks against Israeli targets in the coming weeks.
Izz al-Din al-Qassam Brigades carried out two shooting attacks against Israeli settlers in the occupied West Bank last week, killing four people in one incident, and wounding two in the other.
Yitzhak Aharonovitz, the Israeli internal security minister, said on Saturday he expected the "imminent" arrests of the perpetrators of those attacks.
He said the attacks were not the only attempts by Palestinian fighters to cast a pall over the relaunch of peace talks.
"This week there have been dozens of alerts about attempts to carry out attack in Israel and in Judaea and Samaria [the occupied West Bank]," Aharonovitz said in comments broadcast by Israel’s military radio station.
Mahmoud Abbas, the Palestinian president, and Binyamin Netanyahu, the Israeli prime minister, met in Washington on Thursday to resume direct talks after a 20-month suspension.
Netanyahu and Abbas agreed to keep talking and produce a framework for a permanent peace deal.
After returning from Washington, Netanyahu addressed ministers in the weekly cabinet meeting on Sunday.
"He talked about this being a historic moment for peace," AL Jazeera’s Sherine Tadros, reporting from Jerusalem, said.
"He said Israel needs to start to find creative solutions to the complex questions and issues facing them, none more prominent of course than the question of settlements and whether the partial settlement freeze in the occupied West Bank will be extended past its end of September deadline."
But Hamas, whose fighters routed forces loyal to Abbas to take over the Gaza Strip in 2007, rejects Abbas’s negotiations.
The US, which is brokering the Israeli-Palestinian negotiations, did not invite Hamas to the talks, because it recognises it as a "terrorist organisation." But political observers say that is a misguided approach.
"Sidelining Hamas in any process to craft genuine peace between Israelis and Palestinian is a glaring omission tantamount to having an elephant in the living room," says Larbi Sadiki, a lecturer at the University of Exeter. "Whether it is Obama’s or the UN’s negotiating room, pretending something of that size absent is an exercise in futility."
Sadiki says that, if invited to the negotiations, elements of Hamas would "readily speak directly with Israel,"because they believe that "it is better to get it directly from the horse’s mouth."
Abbas, however, has repeatedly said he will present any peace deal to a national referendum, which would include the people of Gaza and the West Bank.
A vote in favour of any peace agreement would then put heavy pressure on Hamas to accept the will of the Palestinian people.
Abbas broke off the last round of direct talks when Israel launched a military assault on the Gaza Strip in December 2008.
(Agencies and Aljazeera.net English)