KARACHI, Pakistan (AP) _ Thousands of Islamic militants clashed Friday with police, hurling stones, burning cars and setting an American fast food restaurant on fire in the southern Pakistani city of Karachi.
Police fought them back with batons, tear gas and gunshots fired into the air.
Leaders of major Muslim political parties called for a nationwide strike on Monday to protest Pakistan's support of the U.S.-led military strikes in neighboring Afghanistan.
Heavy security was in place in major extremist strongholds, including Karachi, Quetta and Peshawar on Friday. Crowds were generally modest, but in Karachi the demonstrators _ most of them Afghan refugees and ethnic Pashtuns who sympathize with them _ tore through the streets for hours.
One man was injured by gunfire, and several others suffered minor injuries, witnesses said.
Scattered protests and violence, some whipped up by leaders of major Islamic parties in Pakistan, have broken out in some cities since the strikes began Sunday. Friday, the main Muslim prayer day, has become a frequent day of trouble.
The government says things are under control, and President Gen. Pervez Musharraf insists most Pakistanis support his decision to help the United States root out terrorism suspect Osama bin Laden and terrorist installations inside Afghanistan
Musharraf's government said Friday it would deal firmly with anyone who protests violently or acts against Pakistan's national interest.
``There are only a few extremist elements who tried to disrupt law and order, but we have given instructions to the law-enforcement agencies not to allow anybody to take law in their hands,'' Musharraf's spokesman, Maj. Gen. Rashid Quereshi, said in Islamabad.
In Peshawar, armored personnel carriers parked on corners and heavily armed soldiers lined the streets and hunkered down in sandbag bunkers. But when several thousand protesters demonstrated early Friday afternoon, everything stayed peaceful.
Young men shouting ``jihad (holy war) is our way'' were signing up to fight in Afghanistan in support of its rigidly Islamic Taliban. Outside the Madni Mosque, as loudspeakers atop its minarets issued the call to prayer, young men handed money to a bearded man with a sign: ``Give to jihad. Down with America and long live Osama.''
In Quetta, clerics in mosques largely avoided anti-American sentiment Friday as at least 1,000 heavily armed riot police guarded the city, according to the deputy police commander, Hammayoon Jogezai. Much of the unrest this week has been in or near Quetta, in Pakistan's southwest.
Near Chaman, in an area heavily influenced by Afghanistan's Taliban, guards from Pakistan's border militia dug trenches along the border with Afghanistan and set up new lines of barbed wire.
The Karachi restaurant was licensed to KFC, the U.S.-based company. Witnesses said the restaurant covered its sign and logo this week in anticipation of anti-American reaction.
The fire did not do serious damage and just charred the restaurant, and no injuries were reported. Demonstrators then moved on to burn seven vehicles _ two public buses, three cars and two motorcycles. In the eastern Pakistani city of Lahore, police said they quickly deployed officers to the local KFC.
In the mountainous southern city of Jacobabad, soldiers and police patrolled the streets and residential rooftops, tightening security near an air base that government officials and witnesses say is being used by American personnel.
Authorities stopped and questioned drivers along main roads, and police were stationed every half-mile. Roads leading to the Jacobabad air base were blocked.
Pakistani officials confirmed Thursday on condition of anonymity that the country has allowed U.S. military aircraft to land inside its borders and has granted the United States use of at least two air bases during air strikes inside Afghanistan.
The officials emphasized that the Americans were not ground forces and did not characterize them as U.S. military personnel.
The issue is extremely controversial in this Muslim country. The government issued a formal denial Thursday that ``U.S. armed services personnel and aircraft'' were in Pakistan.