CAIRO, Jan 4 (Aswat Masriya) - Three "terrorist" extremists were arrested on Saturday after one soldier was killed while driving a military vehicle in North Sinai's Arish, a military spokesman said.

Terrorist elements targeted an armed forces vehicle with a bomb, which killed Ayman Hassan Ali, the vehicle's driver, the spokesman said in a statement.

Security forces swept the area following the explosion in case another bomb was planted nearby.

A bomb squad defused another explosive device that was planted close to the State Litigation Authority in Salam area in Arish, a security source told Aswat Masriya.

Helicopters flew over Arish, Sheikh Zoueid, and Rafah as part of a security crackdown to pursue extremists in North Sinai.

Army forces, in cooperation with the police, have launched a series of crackdowns in Sinai after extremists had escalated their operations against security forces following former President Mohamed Mursi's ouster last July.