The leader of Pakistan's main Islamic alliance has said there will no let up in protests against cartoons satirising the Prophet Muhammad.
Pakistan has seen a number of protests against the cartoons
Qazi Hussain Ahmed, the leader of six-party MMA, made the comments after being released from house arrest.
In a separate incident 23 people were arrested after two churches were burned down by a mob.
The cartoons, first published in Denmark in September, have angered Muslims across the world.
Islamic tradition prohibits any depiction of Allah or the Prophet.
Several people have died in protests, including five in Pakistan.
Qazi Hussain said his group will carry out a series of rallies in the run-up to US President George W Bush's visit to Pakistan next month.
"Our protests will continue. The European countries should realise the sentiments of Muslims. They should apologise to the Muslim world," another senior MMA leader, Liaqat Baluch, is quoted as saying by the Associated Press.
Qazi Hussain also called for a nationwide strike on Friday and said his campaign was also aimed at President Pervez Musharraf for his "pro-western policies".
On Monday, protests took place in more than a dozen Pakistan towns and cities.
In another incident, police in the city of Sukkur in the southern province of Sindh, police arrested 23 people after two churches were burned down by a mob apparently enraged by reports that a copy of the Muslim holy book, the Koran, had been desecrated.
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 tear gas demonstrators in Islamabad, Pakistan
Troops were called in to assist the police in restoring order after the incident which took place on Sunday.
"We have asked religious leaders to keep people under control and exercise tolerance," Sindh Inspector General of Police Jahangir Mirza told the BBC.
Correspondents say the protests led by Islamist opposition groups in Pakistan against the cartoons have recently broadened into an attack on President Musharraf
Gen Musharraf has condemned the cartoons, which include one portraying the Prophet Muhammad with a bomb in his turban.