A rocket fired from Gaza exploded near an Israeli kindergarten on Tuesday as cross-border violence surged in the approach to the two-year anniversary of Israel's war in the Hamas Islamist-run enclave.

No one was hurt at the preschool but a teenage girl in a nearby building was cut by flying glass in the shower.

"We were lucky," said Ilan Goldsmith, community manager at Kibbutz Zikim, just north of the Gaza Strip. "It exploded at quarter to eight this morning, the exact time when parents are bringing their children in ... 28 children."

The Palestinian-made Qassam rocket corkscrewed into the kibbutz, he said, exploding on a shady path about 10 metres (30 feet) from the kindergarten and two adjacent nursery buildings for the under-three year olds.

Earlier, Israeli aircraft struck targets in Gaza, wounding two Hamas militants and blowing up tunnels under the border with Egypt used to circumvent an Israeli blockade.

"The situation in the south is tense and fragile, and it could deteriorate if a rocket attack causes a large number of casualties," Lieutenant-General Gabi Ashkenazi, the Israeli military's chief of staff, told a parliamentary committee.

An Israeli military spokesman said at least 14 rockets had been fired from Gaza in the past two days. An Israeli air strike in Gaza on Saturday killed five militants from a rocket squad, in the heaviest toll during sporadic clashes this year.

CLAIM OF RESPONSIBILITY

Responsibility for Tuesday's rocket attack was claimed by a group calling itself the Army of Islam, which has the same "global jihad" ideology as the al Qaeda movement. It said it was responding "to the massacres committed by the Zionist enemy".

Hamas leaders have tried to curb rocket fire at Israel from Gaza in recent years, but smaller groups continue to carry out attacks. Israeli forces killed some 1,400 Palestinians in a three-week offensive on Gaza which began on Dec. 27, 2008, after an unofficial truce collapsed under the pressure of sustained Hamas rocket fire and Israeli counter-attacks.

The Israeli army says that more than 200 missiles, rockets and mortars have been fired from Gaza this year.

"We're witnessing a certain escalation," Information Minister Yuli Edelstein told reporters last week at a briefing on Israel's programme to open Gaza's controlled crossing point at Kerem Shalom to more trade.

The capacity of the logistics hub is being expanded from 100 trucks a day to 250, and to 400 by next year to allow more goods into Gaza.

Critics of Israel's three-year-old blockade say it has failed to weaken the grip that Hamas maintains on Gaza's 1.5 million Palestinians and has only made life harder for civilians.

Goldsmith said Zikim residents enjoyed a long period of calm following the war which ended on Jan. 18, 2009, but had recently been expecting a return of the threat of random rocket attacks.

"The early-warning alarm went off and one woman with her kid managed to run home before the rocket exploded," he said, adding that a man delivering propane gas had fainted with shock. (