|Palestinian medical and security officials said at least three people were injured in the Israeli attacks [AFP]
Israel has launched a series of air raids against targets in southern Gaza just hours after Palestinian fighters fired a rocket over the border.
Witnesses and Hamas security officials said late on Saturday that Israeli aircraft struck targets including smuggling tunnels running under the border with Egypt at Rafah within hours.
At least three people were wounded in the attacks, medical workers said.
An Israeli military spokesman confirmed the attacks, saying that one was aimed at "a tunnel dug in the direction of Israeli territory" to carry out attacks.
Early on Saturday, Palestinian fighters fired a rocket from the Gaza Strip into southern Israel, causing no injuries, the Israeli military said.
Gaza is governed by Hamas, the Palestinian faction which is strongly opposed to negotiations with Israel.
Witnesses said one of the tunnels hit by the Israeli raids collapsed, and three Palestinians who were working in it had not yet made it back to the surface.
Another of the strikes struck a former base of the Izz al-Din al-Qassam Brigades, Hamas' armed wing.
The flare-up of violence on the Israeli-Gaza border came just two days after the start of Israeli-Palestinian peace talks in the US.
Fighters from the military wing of Hamas 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.
Hamas has vowed to carry out further attacks against Israeli targets in the coming weeks.
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.
But Hamas, whose fighters routed forces loyal to Abbas to take over the Gaza Strip in 2007, rejects Abbas's negotiations.
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.