Police in the Pakistani capital have used tear gas to disperse people who defied a ban on protests over cartoons satirising the Prophet Muhammad.
Police used teargas in central Islamabad to disperse protesters
Hundreds of protesters armed with sticks and stones evaded cordons and roadblocks to rally in Islamabad.
The cartoons, first published in Denmark in September, have angered Muslims across the world. Several people have died in protests.
Islamic tradition prohibits any depiction of Allah or the Prophet.
An all-day curfew has been imposed in Nigeria's north-eastern city of Maiduguri, where 16 people - mainly from the Christian minority - were killed in riots on Saturday.
Pakistani President Pervez Musharraf has condemned the cartoons, which include one portraying the Prophet Muhammad with a bomb in his turban.
Protests in Pakistan over the last week led to five deaths and prompted the authorities to ban Sunday's demonstration.
Qazi Hussain Ahmad, a senior leader in Pakistan's Islamist opposition alliance, was placed under house arrest before he could travel to Islamabad for the planned march.
30 Sept 2005: Danish paper publishes cartoons
10 Jan 2006: Norwegian publication reprints cartoons
31 Jan: Danish paper apologises
1 Feb: Papers in France, Germany, Italy and Spain reprint cartoons
4-5 Feb: Danish embassies in Damascus and Beirut attacked
6-12 Feb: Twelve killed in Afghanistan protests
13-18 Feb: Violent protests break out across Pakistan
18 Feb: 16 killed in Nigerian protest
19 Feb: Police tearsgas demonstrators in Islamabad, Pakistan
Another opposition leader, Maulana Fazlur Rahman, managed to lead a small group of people into the city centre, chanting slogans against the government and its pro-US policies.
Police fired teargas and warning shots to disperse crowds who disobeyed a ban on gatherings of more than five people.
According to the BBC's Barbara Plett in Islamabad, Sunday's demonstration failed to become the mass rally planned by Islamist leaders.
Rather, she says, it represented the best protesters could muster in the face of massive security measures that have effectively shut Islamabad down.
Many roads into the city have been shut and police have been searching vehicles and taking swift action against anyone who appears to be defying the ban.
Protests led by Islamist opposition groups have recently broadened into an attack on President Musharraf, our correspondent says.
The Danish cartoonist behind some of the drawings has meanwhile said he has no regrets.
Kurt Westergaard - who has been in hiding since a Pakistani cleric offered money for his death - told a Scottish newspaper he had not anticipated the controversy sparked by his work.
He said the cartoons were intended as a protest against double standards in Denmark and Western Europe - a reference to perceived taboos in addressing aspects of Islam.
Denmark's ambassador to Pakistan has returned to his home country, according to the Danish foreign ministry, "because it is practically impossible for him to do his job under the current circumstances".
The Danish embassy in Islamabad was temporarily closed down on Friday.