A group of suspected Hamas fighters were arrested after allegedly returning from training courses in Iran and Syria. About 15 of the suspects were allegedly allowed to cross into Gaza with a cache of weapons and ammunition in ambulances, the Jerusalem military intelligence Web site DEBKAfile said.

Sources told DEBKAfile that the immigration of Hamas fighters coincided with the escalation of conflict between Israel and militants in Gaza. Israeli officials were hesitant to highlight the movement of fighters for fear of angering Cairo, as it expresses its support for Israel's fight against militants.

The report says that Israeli Prime Minister Ehud Olmert doesn't want to embarrass Egyptian President Hosni Mubarak ahead of a visit to the region by U.S. Secretary of State Condoleezza Rice.

Rice is expected to chastise the Palestinians for the increased rocket attacks on southern Israel but also criticize Israel for its blockade on Gaza.

The report says Mubarak may see that as an opportunity to continue supporting Hamas.