Smugglers transporting arms into the Gaza Strip are operating almost freely after a change of leadership in Egypt, Israel's Shin Bet security agency said Friday.

A report by the domestic intelligence agency said with Egypt's new leaders preoccupied with stabilizing their country, "governance in Sinai is not high and this allows smugglers to operate almost without hindrance.

"Today the Egyptian regime's attention is focused on stabilizing the new government and this eases the Sinai smugglers' task," the report said.

The Sinai forms a huge desert buffer zone between Egypt and Israel, which sealed an historic peace treaty in 1979 after fighting two wars against each other in less than a decade.

The Bedouin people of the Sinai, for whom smuggling is a major source of income, was the group mostly involved in getting weapons into Gaza to supply the Palestinian Islamist movement Hamas which controls the enclave and other smaller militant groups, it said

It also reaffirmed Israel's belief that Iran, in seeking to strengthen its influence in the region, was supplying Hamas and Islamic Jihad militants with "choice military-grade weaponry."

It said hundreds of rockets with a range of 20-40 kilometres (12-25 miles), at least 1,000 mortar bombs, some anti-tank missiles and tons of high explosives and raw material to make high explosives had entered Gaza since the start of 2010.

Outgoing Shin Bet chief Yuval Diskin, who hands over the role to his successor Yoram Cohen on Monday, said in a rare speech earlier this week: "In Egypt it is very hard to assess what will happen in the elections expected in the summer ... it's not a good idea to rest on our laurels."

Even under the rule of ousted president Hosni Mubarak, who was considered a partner of Israel in the Middle East, "Egyptian actions did not significantly reduce the scale of munitions smuggling," the report said. But matters have now worsened.

The Shin Bet report said munitions were transported from Iran to Sudan, across Egypt's Sinai Peninsula and through smuggling tunnels into the Gaza Strip.

Sudan accused Israel of launching an air strike in April near Port Sudan airport that killed two people. Khartoum has close ties with Hamas, but denies giving it direct support.

Israel is also suspected of carrying out an air strike on an arms convoy in eastern Sudan in 2009 for which it has neither admitted nor denied responsibility.