< p>TUNIS, Tunisia (AP) — Vandals have burned down a famed mausoleum at a picturesque, much-visited site outside Tunisia's capital, amid tensions between the government and Islamist extremists.

The president's office condemned the arson at the Sidi Bou Said mausoleum, calling Sunday for better security at cultural sites and blaming those who "are trying ... to undermine the country's culture in its historical dimension."

Residents marched to protest the violence. The fire gutted the mausoleum and the roof caved in.

The overnight fire came after five ultraconservative Muslims were detained for burning down another mausoleum near Tunis and a series of similar attacks apparently aimed at destabilizing the government.

Tunisia's government, led by moderate Islamists elected after a revolution in 2011, is struggling against pressure from those who want a strict Islamist state.