SINAI, April 15 (Aswat Masriya) The Egyptian authorities arrested one of the leaders of "Ansar Bayt al-Maqdis" a few hours after a police sergeant was shot dead by unknown assailants in Arish on Monday, North Sinai Security Director said.

The leader, who was not named, was moved to a security headquarter for interrogation about the murder of the police sergeant.

Khalaf Abdel Tawab was shot dead while he was headed to work.

An Egyptian court designated "Ansar Bayt al-Maqdis" as a terrorist group on Monday.

The group has declared its responsibility for killing dozens of policemen, army personnel and tourists after the ouster of President Mohamed Mursi, who hailed from the Muslim Brotherhood, last year.