Tunisia said it would deploy the army to major cities and arrested four people on Thursday after militant gunmen killed 20 foreign tourists visiting the national Bardo museum, the worst attack on the north African country in more than a decade.

Nine people have been arrested in connection with Wednesday’s gun attack in Tunis that left 23 people dead, including 20 foreign tourists, the Tunisian presidency says. It alleged that four were directly linked to the attack and five had “ties to the cell”.

Gunmen stormed Tunisia’s national museum, killing 17 tourists of various nationalities and two Tunisians in an attack that raised fears for the birthplace of the Arab Spring. The brazen daylight assault yesterday sparked panic at the nearby parliament and the National Bardo Museum itself, a magnet for the tourists who …