Egypt has arrested an Israeli man on suspicion of spying and of trying to recruit Egyptian youths to act against the authorities after President Hosni Mubarak's overthrow, sources and the state news agency said Sunday.

Judge Hesham Badawi of the supreme state security prosecution ordered the man to be detained for 15 days on suspicion of "spying on Egypt with the aim of harming its economic and political interests," MENA news agency reported.

A judiciary source said the man was arrested Sunday.

Egypt, which in 1979 became the first Arab state to sign a peace treaty with Israel, has experienced months of political upheaval since protesters overthrew Mubarak, who regularly met Israeli officials and maintained close ties.

The detention may add to tensions raised by a row over the halting of Egypt's gas exports to Israel after a pipeline blast and Cairo's easing of restrictions at a Gaza border crossing that Mubarak had kept very tightly controlled.

MENA said the man worked for Israel's Mossad intelligence service. It named him using Arabic script, but it was difficult to transliterate it accurately in Latin script.

Detention orders of 15 days are often renewed in Egypt if further questioning is deemed necessary.

One judiciary source said the man had been active in Cairo's Tahrir Square, the epicentre of the revolt against Mubarak, after the former president stepped down.

"He was there on a daily basis inciting youths toward sectarian strife. He was distributing money to some of them," the source said, adding he had been encouraging some youths to clash with the army. He said youths reported the man's actions.

Officials at Egypt's Foreign Ministry could not be reached for comment.

Israel's Foreign Ministry said it was not aware of the case.