Hundreds of people have peacefully demonstrated in London's Trafalgar Square to stand up for free speech, rally organisers have said.
The protest was born from a blog site on the internet
The protest was in response to the uproar over cartoons of the Islamic prophet Muhammad, which appeared in some European newspapers.
Organisers said it was not anti-Muslim and warned the British National Party to stay away.
Meanwhile, the Muslim Action Committee staged a counter-protest in Birmingham.
The free speech movement was born from a blog site on the internet and rallied hundreds from across the political spectrum to join Saturday's rally.
Dr Evan Harris MP, Liberal Democrat human rights spokesman, was among those who spoke at the event.
Organiser Peter Risdon said: "We are in favour of free speech and not against Muslims. They are our neighbours and our friends."
Mr Risdon said 600 people had taken part, while police said 250 people were at the rally at its peak.
Initial plans to print the controversial cartoons satirising the Prophet Muhammad onto banners as a way of expressing support for the Danish cartoonists were shelved.
"There is no way in the present climate that they could be construed as anything other than a potential threat," said Mr Risdon.
Police said there had been no arrests but officers did receive a complaint about the message on one protester's placard.
A Scotland Yard spokeswoman said officers spoke to the man and he was later allowed to rejoin the demonstration.
"The complainant stated they felt threatened by a placard they believed depicted the Prophet Muhammad," she said.
"Details of the complaint, together with evidence gathered by police are to be passed to the Crown Prosecution Service."
Meanwhile, nine men wearing black-and-white head scarves and dressed in camouflage clothes were apparently involved in a counter demonstration.
Police informed the men they were free to remain at the event but stayed with the group until they left the square a short while later, partly because some had their faces covered.
A separate counter-protest took place in Birmingham on Saturday morning.
Ismaeel-Haneef Hijazi, of the Muslim Action Committee which was formed in the wake of the controversial publication of the cartoons, said he was calling for "global civility" and was not against the free speech protest organisers' message.
But the group feared the event would be disrupted by BNP members and antagonists.
He said 300 protesters joined a two-hour rally in the city's Victoria Square.
They were concerned the demonstrators in London would use placards and banners depicting the cartoons.
The latest rallies follow demonstrations around the world including a 5,000-strong rally by mainstream Muslim groups in Trafalgar Square in February.