The demonstration in eastern Laghman province briefly threatened to turn into another melee as about 300 protesters brandished sticks and threw stones at the police, who in turned started firing shots in the air, according to an Associated Press photographer at the scene.

Protests erupted in Afghanistan again on Monday against a Florida pastor’s burning of the Quran, making four straight days of demonstrations - some deadly - against the destruction of Islam’s holy book in a country struggling to beat back an insurgency led by Taliban religious extremists.

The demonstration in eastern Laghman province briefly threatened to turn into another melee as about 300 protesters brandished sticks and threw stones at the police, who in turned started firing shots in the air, according to an Associated Press photographer at the scene.

The protest started in Alingar district and the shouting crowd moved towards the provincial capital of Mihtarlam, where they clashed with officers who wanted to keep them out of the city, said Gen. Abdul Aziz Gharanai, the provincial police chief.

However, the protesters dispersed as officers started firing warning shots and no one was wounded, Gen. Gharanai said. The AP photographer also heard no reports of serious injuries.

At least 21 people have been killed in the past three days of protests across the country.

The violence was set off by anger over the March 20 burning of the Quran by a Florida church - the same church whose pastor had threatened to do so last year on the anniversary of the September 11 attacks, triggering worldwide outrage.

The protests began on Friday when thousands of demonstrators in the previously peaceful northern city of Mazar—i—Sharif poured into the streets after Friday’s Muslim prayer services and overran a U.N. compound, killing three U.N. staff members and four Nepalese guards.

The demonstrations have appeared to awaken a simmering anti—foreigner sentiment in the country, where anger about civilian casualties and international contractors making fortunes off the long—running conflict have worn down the welcome for Western forces over more than nine years of fighting.

Meanwhile, NATO said one of its service members was killed Sunday in an insurgent attack in the east. NATO did not disclose other details or the nationality of the dead. The majority of the troops in the east are American.

The latest death makes a total of 102 NATO service members killed so far this year. In the same period of 2010, 129 NATO troops died.

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