An Egyptian security official says authorities have renewed the detention of a U.S.-born Israeli who is being held in Egypt on espionage allegations.

The official says 27-year-old Ilan Grapel will spend 15 more days in detention pending further investigation. The official spoke Saturday on condition of anonymity because he was not authorized to speak to the press.

Grapel was arrested in Cairo two weeks ago.

Egypt says he is a Mossad agent, and pictures of him in Israeli military uniform have been widely published in Egyptian papers. Israel says Grapel was in Cairo working for a legal aid project when he was arrested.

Grapel has been accused of sedition and inciting Egyptians to clash with the country's intern military leadership.

Grapel's family says he was spending the summer in Cairo as an intern at a legal aid group. Israel has denied the 27-year-old Grapel is a spy.

The arrest came as the military faces criticism of how it is running the country and resonates among Egyptians looking for someone outside to blame.

Since Mubarak's ouster, Egypt's military rulers have often warned against unspecified foreign attempts to destabilize the country. Egypt, like other Arab states, has a long history of blaming internal problems on Israeli saboteurs.