Hamas fires barrage of rockets into Israel
Hamas militants in Gaza have fired rockets and mortars into southern Israel following air strikes against the Palestinian territory.
The Israeli raids have killed at least six Palestinians in recent days.
The death of a two-year-old girl in Gaza was initially blamed on an Israeli air strike, but it now appears a botched rocket launch was to blame.
The rocket barrage follows months of relative restraint by Hamas, which has been observing a fragile truce.
Israeli communities near the Gaza border have been placed on heightened alert.
Meanwhile, a shadowy militant group said it had carried out an attack on the Israel-Egypt border on Monday.
In a video, the Mujahideen Shura Council of Jerusalem identified the attackers as an Egyptian and a Saudi. Both were killed in clashes with Israeli forces after setting off an explosion in which an Israeli working on a border security fence died.
Israeli security officials said at last 40 rockets fired at southern Israel on Tuesday, reported Reuters news agency.
The attacks followed an Israeli air strike early in the day near Deir el-Balah in Gaza that killed two Palestinians. Medical officials in Gaza quoted by the AFP news agency said the two were both 17-year-olds.
The Israeli military said it had hit a "terrorist squad identified handling an explosive device" near the security fence in the central Gaza Strip.
Later on Tuesday, Israel attacked a group of militants it said had been firing rockets, and Palestinian doctors said at least one man was seriously injured.
Four other Palestinians have been killed in similar Israeli raids over the past few days.
Meanwhile, late on Tuesday, a rocket hit a house in an Israeli village near the Gaza border, Associated Press quoted police spokesman Micky Rosenfeld as saying. Rescue workers said three people were injured.
In a rare move, Hamas spokesman Fawzi Barhoum said earlier in the day that Hamas was responsible for the rocket attacks, and that the Israeli strikes had prompted the group's military wing "to take a firm stance" and launch rockets.
Gaza-based al-Aqsa TV said the al-Qassam Brigades had fired 10 Grad missiles into southern Israel "in retaliation for the occupation's crimes".
The BBC's Jon Donnison in Ramallah says it is the first time Hamas has said it was directly involved in attacks against Israel for more than a year, although Israel believes Hamas allows smaller militant groups to carry out strikes.
Our correspondent says it is not clear why Hamas has chosen this moment to re-engage with Israel directly.
Egyptian officials are believed to be making efforts to restore calm.
Monday's attack from the Egyptian side of Israel's southern border has increased Israeli concerns about lawlessness in the region since last year's ousting of President Hosni Mubarak.
Later on Monday, two suspected Palestinian militants on a motorbike were killed in an Israeli air strike near the town of Beit Hanoun in Gaza. Israel says the pair was planning an attack.