Afghan police say one protester has died after crowds demonstrating against cartoons satirising the Prophet Muhammad attacked Nato-led troops.
Protesters tried to break into the US embassy in Kabul
Norwegian soldiers fired in the air after protesters tried to break into their base in Maymaneh, Nato said. British reinforcements are being sent.
In Kabul, police prevented protesters from reaching the Danish embassy. Jalalabad and Herat also saw protests.
Five died in Afghanistan on Monday as protesters vented fury over the images.
The cartoons, originally published in a Danish newspaper, have been denounced throughout the Islamic world.
Islamic tradition explicitly prohibits images of Allah and the Prophet Muhammad.
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
- Hundreds of Muslims gather in Cotabato, in the southern Philippines, demanding Denmark punish the Jyllands-Posten paper for publishing the cartoons
- Norway demands compensation from Syria after its embassy in Damascus was set on fire on Saturday
A spokesman for the Nato-led International Security Assistance Force peacekeeping force told the BBC that British reinforcements were being sent to Maymaneh to secure the airfield after the violence on Tuesday.
The circumstances surrounding the shooting of the protester in Maymaneh are still not clear.
A spokesperson for the Nato-led peacekeeping force in Afghanistan said a crowd several hundred strong attacked and tried to break into a compound of Norwegian-led troops.
She said they fired warning shots and tear gas to disperse the crowd who appeared, she said, to be throwing some sort of grenade.
She said Nato troops had not fired into the crowd.
A senior Afghan police officer, Muhammad Naim, told the BBC that one man had been shot dead and two more injured after the crowd burned the guard room of the provincial reconstruction team (PRT).
He said it was not the police who shot the protester and that the demonstrators were moving towards the Nato troops when the death occurred.
The PRT, which is engaged in rebuilding projects, comprises about 100 solders from Norway and Finland.
Reports from Maymaneh say two protesters are still lying inside the troops' compound. It is not clear if they are injured or dead.
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.
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 Isaf headquarters. They also 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 President Hamid Karzai and US President George Bush.