Some 128 people, mostly security officers, were injured and 120 people were arrested in unrest on Sunday following demonstrations that drew around 37,000 Moroccans in dozens of cities and towns, according to Interior Minister Taib Cherkaoui.
Protesters were demanding King Mohammed give up some powers, dismiss the government and clamp down on corruption.
Cherkaoui told a news conference that the protests had been peaceful but minors and troublemakers had committed acts of vandalism in Marrakesh, Tangier, Sefrou and other towns.
The charred bodies were found in a bank in the northern town of Hoceima. Cherkaoui said shops, public institutions, banks and cars had been damaged in various cities hit by the unrest.
"Some troublemakers forced their way into a customs building and stole drugs and alcohol," Cherkaoui said.
He said 120 people had been arrested.
Sunday's protests were the biggest demonstrations in Morocco since uprisings in Egypt and Tunisia overthrew their longtime presidents and sent a wave of protests across the Arab world.
While placards and slogans did not directly attack the king, it was the first time demands for constitutional reform had been publicly expressed by ordinary Moroccans.
Morocco, an ally of the West with a reformist monarch and growing economy, is seen by some experts as less susceptible than its neighbors to the unrest buffeting the Arab world.
