* Saudi Arabia is main U.S. regional ally
* Film has sparked unrest in Libya, Egypt and Yemen
DUBAI, Sept 13 (Reuters) - Saudi Arabia on Thursday condemned a film Muslims consider blasphemous to Islam but also denounced the violent anti-American protests it has sparked in some Muslim countries.
Four U.S. officials including the ambassador to Libya were killed in the east Libyan city of Benghazi on Tuesday night after anger over the film boiled over and there have also been protests against its content in Egypt and Yemen.
"Saudi Arabia has expressed ... its condolences to the United States of America for the victims of violent actions in Libya that targeted the American consulate in Benghazi," state news agency SPA reported, citing a senior official.
The kingdom also denounced what it called an "irresponsible" group which produced the film deemed insulting to the Prophet Mohammad and condemned "the violent reactions that occurred in a number of countries against American interests."
Saudi Arabia, the world's top oil exporter, is Islam's birthplace and a main regional U.S. ally.
The United Arab Emirates, another Gulf ally of the United States, also condemned the "the recent violent incidents that led to the death of the U.S. ambassador to Libya," state news agency WAM reported, citing Foreign Minister Sheikh Abdullah bin Zayed.
Clips of the film posted on the Internet show an amateurish production portraying the Prophet Mohammad as a womaniser, a homosexual and a child abuser.
Hundreds of Yemeni demonstrators stormed the U.S. embassy compound in Sanaa on Thursday in protest and clashes with security forces there killed at least one person and injured 15.
In Egypt, protesters hurled stones at a police cordon around the U.S. embassy in central Cairo after climbing into the embassy and tearing down the American flag. The state news agency said 13 people had been injured in violence which erupted on Wednesday night after protests on Tuesday.