The U.S. is sending spies and drones to Libya to speed the search for suspected al-Qaida sympathizers who killed U.S. ambassador Chris Stevens and three other Americans.

The investigation is complicated by a chaotic security picture and limited American and Libyan intelligence resources.

FULL COVERAGE: Embassy Attacks

The U.S. has already sent an FBI investigation team to Libya and increased drone flights over the country, hunting those who turned a demonstration over an anti-Islamic video into a violent attack on the U.S. consulate in Benghazi.

But U.S. officials say the Americans have found no evidence pointing conclusively to a particular group or to indicate Tuesday's attack was planned. They spoke anonymously because they were not authorized to discuss the investigation publicly.

Sydney police clash with film protesters

Riot police have clashed with about 200 protesters who rallied in downtown Sydney as part of global demonstrations against an anti-Muslim film produced in the United States.

Ten Network television news showed a policeman knocked unconscious and reported several people injured among the mostly male crowd Saturday that targeted the U.S. Consulate.

Police would not immediately confirm injuries or say whether arrests had been made. Police used pepper spray against protesters, some of whom chanted: "Obama, Obama, we love Osama."

U.S. diplomatic posts around the world have been targeted in recent days by protests against the film, which ridicules the Prophet Muhammad.

Tunisia's ruling party condemns US embassy attack

Tunisia's ruling moderate Islamist party has condemned an attack on the U.S. Embassy, saying such violence threatens the country's progress toward democracy after decades of dictatorship.

Protesters on Friday briefly stormed the U.S. Embassy compound in Tunis and ransacked an adjacent school. Two demonstrators died and 40 people were injured.

The attack was part of a wave of demonstrations across the Muslim World to protest a film created in the U.S. that insults the Prophet Muhammad.

The youth wing of the moderate Islamist Ennahda party said in a statement that both the film and the violence should be condemned.

The statement, emailed early Saturday, warned that "enemies of the revolution" were manipulating anger to divide the country and prevent Tunisia from building a robust democracy.

(Copyright 2012 by The Associated Press. All Rights Reserved.)