In a move that could escalate tensions around the Arab world, the leader of the Hezbollah militant group called for protests against the movie, saying protesters should not only ‘express our anger’ at U.S. embassies but urge leaders to act.

The film, which denigrates Islam’s Prophet Muhammad, has sparked violent protests in many Muslim countries in recent days, including one in Libya in which the U.S. ambassador was killed. The U.S. has responded by deploying additional military forces to increase security in certain hotspots.

In a televised speech, Hezbollah leader Sheik Hassan Nasrallah said the U.S. must be held accountable for the film, which was produced in the United States. The U.S. government has condemned the film.

‘‘The ones who should be held accountable and boycotted are those who support and protect the producers, namely the U.S. administration,’’ Nasrallah said. He called for protests on Monday, Wednesday, Friday, Saturday and Sunday.

He urged protesters to call on their leaders to express their anger too.

‘‘We should not only express our anger at an American embassy here or there. We should tell our rulers in the Arab and Muslim world that it is ‘your responsibility in the first place’ and since you officially represent the governments and states of the Muslim world you should impose on the United States, Europe and the whole world that our prophet, our Quran and our holy places and honor of our Prophet be respected,’’ he told his followers in a televised speech.

Nasrallah said he waited to speak out about the film until Sunday, when Pope Benedict XVI ended his three-day trip to Lebanon.

In Pakistan, police fired tear gas and water cannons at the protesters in Karachi after they broke through the barricade and reached the outer wall of the U.S. Consulate, police officer Mohammad Ranjha said. The protesters threw stones and bricks, prompting the police to beat back the crowd with their batons. The police and private security guards outside the consulate also fired in the air to disperse the crowd.

One protester was killed during the clash, said Ali Ahmar, spokesman for the Shiite Muslim group that organized the rally.

An official with the main ambulance service in the city, Khurram Ahmad, confirmed they carried away one dead protester and 18 others who were injured.

All Americans who work at the consulate, which is located in the heart of Karachi, were safe, Rian Harris, a spokeswoman for the U.S. Embassy in Islamabad, said.

Thousands more held peaceful demonstrations against the film in other parts of the country, including the eastern city of Lahore and the northwest city of Dera Ismail Khan.

The demonstration in Lahore was organized by Jamaat-ud-Dawa, believed to be a front organization for a powerful militant group blamed for attacks in the Indian city of Mumbai in 2008 that killed over 160 people. The protesters shouted anti-U.S. slogans and burned an American flag.

‘‘Our war will continue until America is destroyed!’’ shouted some of the protesters. ‘‘Dog, dog, America is a dog!’’ chanted others.

The head of Jamaat-ud-Dawa, Hafiz Mohammad Saeed, who has a $10 million U.S. bounty on his head, addressed the crowd and demanded the Pakistani government shut down the U.S. Embassy and all consulates in the country until the filmmakers are punished.

The protests were set off by a low-budget, crudely produced film called ‘‘Innocence of Muslims,’’ which portrays Muhammad as a fraud, a womanizer and a child molester. A 14-minute excerpt of the film, which is both in English and dubbed into Arabic, has been available on YouTube, although some countries have cut access to the site.

The violence began Tuesday when mainly Islamist protesters climbed the U.S. Embassy walls in the Egyptian capital of Cairo and tore down the American flag from a pole in the courtyard.

Chris Stevens, the U.S. ambassador to Libya, also was killed Tuesday along with three other Americans, as violent protesters stormed the consulate in Benghazi. President Barack Obama has vowed that the attackers would be brought to justice but also stressed that the U.S. respects religious freedom.