"We will continue to take action against terrorist elements ... in the Gaza region and the West Bank without letting up."
'Blow to Olmert'
But Sami Abu Zuhri, a Hamas official, described the mortar-bomb attack as a blow to Olmert's credibility.
He said: "Olmert is telling lies in a hopeless attempt to sell a false victory against Palestinian resistance."
Izz al-Din al-Qassam Brigades, the military wing of Hamas, claimed responsibility for the mortar attack.
More than 285 rockets have been launched from Gaza since May 15, killing two Israeli civilians, wounding more than 20 others and sending hundreds fleeing from the southern town of Sderot.
Sunday's developments came after reports that Hamas might be considering a one-year ceasefire with Israel.
The Egyptian Al-Ahram daily carried an interview with Moussa Abu Marzouk, Hamas's deputy political leader, in which he said: "We may agree to a one-year ceasefire. Both parties have to abide by it."
Abu Marzouk, who along with Khaled Mashaal, the Hamas leader, lives in exile in Syria, demanded that Israel also agree to a truce with Hamas, saying the only way for success was calm on both sides.
"Hamas is trying to draw us [Israel] into their civil war"
Zafon, Beersheva, Israel
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Several senior Hamas leaders have been in Cairo over the past week for talks with Egyptian officials on ways to end the fighting with Israel.
Mohammad Nazal, a member of the Hamas political bureau, confirmed that Hamas was considering a truce.
He said: "Some private ideas were presented to Hamas [by Egyptian mediators] to reach a truce with Israel, and Hamas is about to undertake a suitable decision."
Israel said it was sceptical of Hamas's intentions.
Mark Regev, a foreign ministry spokesman, said: "The current ceasefire in Gaza is unfortunately a sham. It would seem that before we talk about expanding the ceasefire, we should first get it right."
Hamas wants to get Israel to extend any Gaza ceasefire to the West Bank, where Israeli troops frequently conduct arrest raids against fighters.
Under a plan being worked out by Abbas, Gaza fighters would halt rocket fire for a month to allow for negotiations on a more comprehensive ceasefire that would include the West Bank.
On Saturday, Al Jazeera reported that Ismail Haniya, the Palestinian prime minister, had nominated Ghazi Hamad for the post of interior minister.
|As a spokesman, Hamad has been one of the|
most visible faces of Hamas in recent months
Hamad is one of the leading members of Hamas.
Al Jazeera's correspondent reported that many members of Fatah had supported his nomination.
Hamad has been serving as a spokesman for the prime minister and is so far the only candidate for a post that has been a source of great dispute in the formation of the Palestinian unity government.
The previous incumbent resigned saying it was an empty position. Although the interior minister is nominally responsible for security, in reality armed groups within Hamas and Fatah control affairs.