Nato has sent British reinforcements to a riot-hit Afghan town after crowds protesting at cartoons satirising the Prophet Muhammad attacked peacekeepers.
Protesters tried to break into the US embassy in Kabul
The UK troops were sent to the airfield at Meymaneh, in the north-west.
The move came after three protesters died as they tried to storm the town's Norwegian-led peacekeeping base. The cause of their deaths is unclear.
On Monday, five people died as protests over the cartoons, first published in Denmark, swept across Afghanistan.
The director of health for Faryab province told the BBC that three people had been killed and 30 injured in Meymaneh.
A Nato spokeswoman said a crowd of several hundred people had tried to break into a compound of the Norwegian-led provincial reconstruction team in Meymaneh.
The team, which is engaged in rebuilding projects, comprises about 100 soldiers from Norway and Finland. The UK said an initial 30 troops were sent to help, rising to a full complement of 120.
The spokeswoman said Nato troops there fired warning shots and tear gas to disperse the protesters, but the troops had not fired into the crowd. Protesters threw stones and at least one hand grenade in response, she said.
The provincial deputy governor, Sayed Ahmad Sayed, told AFP news agency that Afghan police had opened fire in response to gunfire from the crowd.
But a senior Afghan police officer, Muhammad Naim, told the BBC it was not the police who shot the demonstrators.
Norway's defence ministry said five Norwegians had been hurt in the riot.
The Nato spokeswoman said order had been restored by early evening.
The Nato-led International Security Assistance Force (Isaf) would not say how many reinforcement troops had been sent to Meymaneh.
The UN has withdrawn some staff from the town.
The cartoons, originally published in a Danish newspaper, have been denounced throughout the Islamic world.
Tensions over the cartoons continued around the world on Tuesday:
- About 5,000 people take to the streets in Peshawar, in Pakistan's North-West Frontier Province
- Denmark says it holds Iran responsible after its Tehran embassy was attacked on Monday; the embassy is pelted with petrol bombs and stones for a second day on Tuesday
- Several hundred Muslims protest in Muzaffarabad, capital of Pakistan-administered Kashmir
- Hundreds of Muslims gather in Cotabato, in the southern Philippines, demanding that Denmark punish the Jyllands-Posten newspaper for publishing the cartoons
- Norway demands compensation from Syria after its embassy in Damascus was set on fire on Saturday
It is the third day of protests in Afghanistan against the controversial cartoons.
30 Sept 2005: Danish paper publishes cartoons
20 Oct: Muslim ambassadors complain to Danish PM
10 Jan 2006: Norwegian publication reprints cartoons
26 Jan: Saudi Arabia recalls its ambassador
30 Jan: Gunmen raid EU's Gaza office demanding apology
31 Jan: Danish paper apologises
1 Feb: Papers in France, Germany, Italy and Spain reprint cartoons
4 Feb: Syrians attack Danish and Norwegian embassies in Damascus
5 Feb: Protesters sack Danish embassy in Beirut
On Monday, three people were killed in Laghman province and two near the main US air base at Bagram - although the US has had no involvement with the images.
In the capital Kabul on Tuesday, police prevented protesters from reaching the Danish embassy.
There is a heavy security presence in Kabul to try to prevent a repetition of Monday's violence.
About 200 people marched through the city on Tuesday. Some threw stones at the headquarters of Isaf, and others tried to break into the US embassy.
The BBC's Bilal Sarwary says police outside the headquarters of the US-led military coalition fired shots in the air to deter the protesters, who were demanding the expulsion of Danish diplomats from Afghanistan.
They also denounced Afghan President Hamid Karzai and US President George W Bush.
There were also protests in the cities of Jalalabad and Herat.