EL-ARISH, Egypt (AP) — Security officials say unidentified gunmen shot and killed an Egyptian policeman in northern Sinai's main city of el-Arish.

The officials say the 27-year-old policeman was in a car and wearing civilian clothes when the gunmen shot him dead Saturday on a main street in the city.

On Sunday, airport officials said U.S. Undersecretary of Defense for Intelligence Michael Vickers arrived to Cairo for two days of meetings to discuss security problems in the Sinai Peninsula.

All officials spoke on condition of anonymity because they were not authorized to speak to reporters.

During the past two years of political turmoil in Egypt, Islamic militants in Sinai have gained strength. They are suspected of killing 16 Egyptian soldiers in August, as well as launching cross-border attacks into neighboring Israel.