Islamabad, Pakistan ? Pakistani security forces arrested hundreds of Islamic hard-liners, virtually sealed off the capital and used gunfire and tear gas Sunday to quell protests against caricatures of the Prophet Muhammad.

Pakistan had banned protests after riots killed five people in two cities last week.

Elsewhere in the Muslim world on Sunday, demonstrators with wooden staves and stones tried unsuccessfully to storm the U.S. Embassy in Indonesia, while tens of thousands rallied in the Turkish city of Istanbul and complained about negative Western perceptions of Islam.

Troops patrolled the deserted streets of the northern Nigerian town of Maiduguri, where thousands of Muslims attacked Christians and burned churches Saturday, killing at least 15 people during a protest over the cartoons. Most of the victims were beaten to death by rioters.

In Saudi Arabia, newspapers ran full-page apologies by Jyllands-Posten, the Danish newspaper that first ran the caricatures in September. The newspaper’s Web site said businesses placed the ad on their own initiative, using an apology issued by the newspaper late last month. It did not identify the companies or say if they were Danish.

Boycotts of Danish products throughout the Muslim world have taken a heavy toll on Denmark’s exporters, especially those selling Denmark’s famed dairy products.

Third week of protests

The cartoons, which have been reprinted by other Western publications, have outraged Muslims. But protests over the past three weeks have grown into a broader anger against the West in general, and Israel and the United States in particular.

Demonstrations have turned increasingly violent and claimed at least 45 lives worldwide.

On Sunday, thousands of police and paramilitary troops manned armored personnel carriers and sandbag bunkers in and around Islamabad to block a planned rally organized by a coalition of hardline Islamic parties that sympathizes with the former Taliban regime in Afghanistan and is fiercely anti-American.

As roadblocks went up around the capital, authorities declared they would arrest anyone joining a gathering of more than five people.

Maulana Fazlur Rahman, an opposition leader who denounced the government ban as unconstitutional, was allowed to stage a small rally with eight other opposition lawmakers and a few supporters. They chanted “God is great!” and “Any friend of America is a traitor.”

But police fired tear gas and guns to chase off hundreds of stone-throwing protesters who tried to join the rally and then enter an enclave where most foreign embassies are. The three-hour clash left the street littered with rocks and spent tear gas shells. An Associated Press reporter saw two injured police, one bleeding from his head, and several injured protesters.

Qazi Hussain Ahmad, a top leader of the hardline Islamic coalition, the Mutahida Majlis-e-Amal (United Action Forum), was confined to his Lahore residence and others were detained or told to stay at home, police said.

“These people could create problems of law and order,” said Chaudhry Shafqaat Ahmed, chief investigator of the Lahore police.

In Karachi, Pakistan’s largest city, police said 15,000 coalition supporters, most wearing white shrouds of mourning splashed with red paint to symbolize their willingness to die defending the prophet’s honor, rallied peacefully.

Other religious tension

Hundreds of Muslims burned a church in the southern city of Sukkur. No worshippers were inside at the time, but one person was hurt afterward when police fired tear gas.

Local police chief Akbar Arian said the riot was not sparked by the cartoons but by allegations that a local Christian had burned pages of Islam’s holy book, the Quran – another sign of the heightened sectarian tensions in this overwhelmingly Muslim nation.