The Israeli military reports that it has killed six Palestinian militants in separate incidents in and around Gaza.
The Hamas men reached a kibbutz before being shot dead
It said two gunmen from the militant Hamas group were killed on Israeli territory after cutting through the border fence.
Another two militants were shot after planting a bomb near the border with Egypt, the army added.
It also said troops had returned fire at two militants who attacked an army vehicle, apparently killing both.
The incident happened near the Kissufim crossing between Gaza and Israel.
Israel has just ended a massive offensive into the northern Gaza Strip, which it said was to prevent the firing of makeshift rockets at Israeli territory nearby.
The top United Nations diplomat in Gaza has characterised the Israeli operation, which focused on Jabaliya refugee camp, as a "gross violation of international and humanitarian law".
The head of the United Nations Relief Works Agency (Unrwa), Peter Hansen, said at least 90 homes had been destroyed and up to 700 Palestinians made homeless in the operation, codenamed Days of Penitence.
Hundreds of Jabaliya residents have been made homeless
"I am protesting every time it happens. Most of what we have seen here in Jabaliya over the last two weeks is a gross violation of international and humanitarian law," he said during a tour of Jabaliya.
The two-week incursion left at least 100 Palestinians, at least one third of them civilians, dead.
One Israeli soldier was killed in an ambush by Palestinian militants and two Israeli toddlers were killed by rocket fire.
Mr Hansen was involved in a furious row with Israeli authorities during the offensive, when Israel claimed a UN ambulance had been used by Palestinian militants to transport weaponry. It later retracted the accusation.
The two militants who managed to infiltrate Israel were spotted soon after cutting through the security fence that surrounds the Gaza Strip.
They got as far as an orchard several hundred metres from the Holit kibbutz, or collective farm.
One of the men was killed by Israeli gunfire, while the other blew up, as he was reportedly wearing an explosive belt, the Israeli military said.
Hamas did not say exactly what the mission had been, but it is likely that they planned a suicidal raid on the farming community, the BBC's Alan Johnston in Gaza says.
The army patrols and monitors Gaza's perimeter fence extremely carefully, and militants very rarely manage to penetrate the defences.
This is the second time in six weeks that Hamas attackers have been able to get into Israel itself and start to close in on a kibbutz before being killed, our correspondent says.
Israel has occupied Gaza since capturing the territory in 1967.
Israeli Prime Minister Ariel Sharon is planning to withdraw settlers and Israeli soldiers from the 40 km long strip, which is home to 1.3 million Palestinians.
Approximately 8,000 settlers from Gaza, and the troops who protect them, are expected to leave Gaza by the end of 2005, though Israel will maintain control of Gaza's borders, coastline and airspace.