Attack kills 5 Israeli soldiers at Gaza checkpoint
Israeli helicopters attack targets in Gaza
Hamas said the tunnel took four months to dig.
GAZA CITY (CNN) -- Five Israeli troops were killed Sunday when Palestinian militants set off an explosion in a tunnel beneath an Israeli military checkpoint and opened fire on the checkpoint as well, an Israeli official said.
The Palestinian militant group Hamas said it had carried out the attack near Rafah with another group called the Fatah Hawks.
Early Monday, two Israeli Apache helicopters fired at least six missiles into Gaza City, said CNN producer Talal Aburahma, who witnessed the incident.
"In a security forces operation tonight in Gaza City, the IAF (Israeli Air Force) targeted two buildings used by terrorist organizations as part of the weapons manufacturing industry in the Gaza Strip," said a release from the Israel Defense Forces.
"The buildings were used by the Hamas terror organization for the manufacturing of different types of explosives, including mortar shells and explosive devices, which [were] used by the organization to carry out terror attacks aimed against Israeli citizens and IDF soldiers."
The IDF did not comment on the reported third target, but Palestinian security sources said it was the house of a Hamas activist in southern Gaza City, which was empty when it was struck.
No casualties were immediately reported, according to Palestinian medical sources.
After the checkpoint attack, six people were taken to hospitals -- four of them badly hurt, one with moderate injuries and one lightly injured, medical sources said.
Sunday's blast took place beneath an international terminal that was recently opened to serve Palestinians who move between Egypt and Gaza.
Raanan Gissin, a senior aide to Israeli Prime Minister Ariel Sharon, called it a sign that terrorists are trying to prevent moves toward normalization in the area -- and he called on Palestinian leadership to take action against such groups.
The attack "indicates that unless there is decisive and sustained effort taken to dismantle the terrorist organization, it will be impossible to move towards normalizations and towards political negotiations. That's the message of today's attack," Gissin told a news crew. "And I think the responsibility on that lies with the Palestinian Authority."
He also called on both Egypt and Palestinian security forces to take actions to prevent the digging of tunnels.
He said Israel will take "the necessary measures" to avoid such attacks unilaterally -- and will "use harsher measures" -- but "we much prefer" to work with Egypt and the Palestinians to do so.
Asked whether the attack and ongoing violence in the area may delay plans for an Israeli unilateral withdrawal from Gaza, Gissin responded, "Nothing in the world is going to postpone the timetables and the decision that has been taken by the government for unilateral withdrawal."
He added, "But there is another alternative ... for the Palestinians with the help of the Egyptians to help us coordinate the withdrawal" and assume security responsibility over the area.
Hamas is a Palestinian Islamic fundamentalist organization whose military wing, Izzedine al Qassam, has admitted responsibility for terrorist attacks against Israeli civilians as well as attacks against the Israeli military.
There was no immediate information available on the Fatah Hawks, though it was believed to be linked to the Fatah movement formerly led by Yasser Arafat, who died last month.
Israeli military sources said it was a coordinated attack, with Palestinians firing mortar shells and guns at the post when the explosives were detonated.
Israeli military sources also said one Palestinian was killed. Two armed Palestinians approached the checkpoint after the explosion and opened fire. Israeli soldiers fired back, killing one of them, the military sources said. The other Palestinian escaped, they said.
In a pamphlet distributed after the attack, Hamas said it had used 1.5 tons of explosives and had recorded video of the incident.
Palestinians have used tunnels in the area to smuggle weapons from Egypt. Israel has carried out operations to crack down on the smuggling.
Shell explosion in schoolyard
An Israeli tank shell exploded in a schoolyard in Gaza on Sunday morning, wounding eight Palestinian schoolchildren, Palestinian medical and security sources said.
The children, between 6 and 12, suffered moderate to light injuries, the sources said.
The violence happened in Khan Yunis in central Gaza.
Israeli military sources said that forces in the area identified what they thought were many mortar shells being fired toward Israeli settlements nearby.
In response, the forces fired toward the positions with light weapons, but did not fire a tank shell, the military sources said.