Egypt has for the first time linked Palestinian militants to suicide attacks in the Sinai last month.
Twenty-three people died in last month's triple blasts
An interior ministry statement said the group behind the attacks, al-Tawhid wa al-Jihad, had opened channels of communication with the militants.
It adds at least two Egyptian militants had been to Gaza and one of them had been trained in the use of explosives.
Twenty-three people were killed in triple bomb attacks on the tourist resort of Dahab on 24 April.
The Egyptian authorities have not accused any of the known Palestinian groups, such as Hamas or Islamic Jihad, of supporting the Sinai bombers, our correspondent says.
They have also denied that al-Qaeda could have had a hand in the attacks.
Al-Tawhid wa al-Jihad is also suspected of previous attacks on the Taba and Sharm al-Sheikh resorts.
BBC Cairo correspondent Heba Saleh says the authorities in Cairo have given no indication of what they believe to be the motivations of the Palestinians they accuse of supporting the Egyptian attackers.
The Egyptian government is uneasy about the election of a Hamas government in the Palestinian territories because it fears that it would provide a boost to both moderate and extreme Islamists in Egypt.