(CNN) -- Eleven people were killed and an Italian consulate was burned in Libya on Friday night during protests to denounce the publication of cartoons depicting the Prophet Mohammed, sources in Libya said.
There also was a "high number" of injuries, said an official with the Italian Embassy in Tripoli.
In the port city of Benghazi in northeast Libya, protesters set the Italian Consulate on fire, but it was safely evacuated and no employees were injured, said Francesco Trupiano, Italy's ambassador to Libya.
"It was peaceful, then it became violent," Trupiano said of the protests in Libya's second-largest city. He said he doubts the consulate will close.
Trupiano speculated that the consulate was targeted because it is the only Western consulate in the city. However, many of the protesters said they were angry because Italian Reforms Minister Roberto Calderoli recently flaunted a T-shirt displaying one of the controversial cartoons on state TV this week.
Prime Minister Silvio Berlusconi has asked Calderoli to resign.
Another demonstration was held in Sebha, where demonstrators gathered after Friday prayers and issued a statement urging respect for religious shrines and beliefs.
The state-run Libyan news agency, Jamahiriya, or Jana, reported on its Web site that the casualties occurred when protesters clashed with police. The public prosecutor has been asked to investigate the way police dealt with the demonstrators, the news agency said.
Benghazi, in northeast Libya, is the country's second-largest city. Sebha is in central Libya.
Jana described the protests as massive but peaceful. It gave no crowd estimates.
The government "strongly denounces" the actions of those who burned part of the Italian consulate, Jana reported. Police were able to prevent most of the attackers from entering the building, but a few went inside and some vehicles outside were burned, the news agency reported.
"The participants in this demonstration expressed in a statement their denunciation and condemnation of such encroachment on Islam and Muslims, stressing the necessity to condemn and criminalize this heinous action," Jana reported.
Protests over the cartoons have escalated in recent weeks, more than four months after they first appeared in a Danish newspaper in September. They were later reprinted by other publications, mostly in Europe. Muslims consider depictions of Mohammed blasphemous.
A written statement released by protesters in Benghazi said they consider Denmark's publication of the cartoons "a direct hostile action."
The statement hailed the government's closure of Libya's embassy in Denmark and urged the Arab League and the Organization of Islamic Conferences to encourage boycotts of any nation that "may dare to touch our religious and historic symbols."
Demonstrators, some of whom set the Danish flag on fire, also appealed to economic institutions to ban the imports and consumption of goods produced in Denmark.