Hamas has vowed to carry out attacks on Israel that could include suicide bombings in response to an Israeli air strike on the Lebanese village of Qana that killed 40 civilians.
"In the face of this open war against the Arab and Muslim nations all options are open, including striking the depth of the Zionist entity," Mushir al-Masri, a senior Hamas lawmaker, said.
Palestinian Islamic Jihad senior commander Hani Owijan, who was killed yesterday in the West Bank city of Nablus
Asked if that meant suicide bombings against Israelis, he said: "All options are open. Every means is allowed. This is a crime and state-terror and a crossing of all red lines."
Hamas carried out nearly 60 suicide bombings against Israelis during a Palestinian uprising that began in 2000, and its armed wing has fired homemade rockets from Gaza into Israel.
Shortly after Hamas issued its statement, a rocket fired from Gaza slammed into the Israeli border town of Sderot.
Medics said a 29-year-old woman was moderately wounded. Hamas's armed wing claimed responsibility for the launch.
Besides its offensive in Lebanon against Hizbollah, Israel has been engaged in an offensive against Palestinian militants for more than a month since militants, including members of Hamas, abducted an Israeli soldier in a cross-border raid from Gaza.
Yesterday, Israeli troops killed two Islamic Jihad militants, including the man the group described as the leader of its militant wing in the West Bank city of Nablus.
Hani Awijan (29) was reportedly shot by Israeli undercover troops trying to arrest him while he was playing football with friends and relatives. Israel Radio said Awijan was responsible for a series of attacks on Israelis.