Speaking to reporters, he asked for the country to unite behind his efforts to secure General Pinochet's release.

Chilean police have stepped up security outside a number of public buildings in the capital, Santiago, and the British embassy has closed its consulate in the coastal city of Valparaiso.

Protests from both sides continue in Chile

Britain also cancelled the visit of a warship to a Chilean naval fair next week.

The Chilean Interior Ministry has urged demonstrators not to break the law and criticised those who have burnt Spanish and British flags during protests.

In Santiago, supporters of Augusto Pinochet have continued to picket the Spanish embassy and the British ambassador's residence but the violent scenes of the last few days have not been repeated.

Diplomatic moves

Mr Insulza: Warning not to expect immediate results

Attention in Chile is now focusing on Foreign Minister Jose Miguel Insulza's second day in London pressing the UK Government for General Pinochet to be allowed to return to Chile rather than be extradited to Spain.

Spanish judge Baltasar Garzon's request for the general's extradition implicates him in 3,178 murders or "disappearances" during his 17 years of power in Chile.

Jose Miguel Insulza: Chile can't accept Spanish trial

Mr Insulza told BBC Radio 4's Today programme that it should be up to Chileans to decide how to deal with General Pinochet.

"The Chilean people have to be allowed to judge and decide how they are going to deal with their past," he said, adding that General Pinochet would face legal action if he was returned to Chile.

Robin Cook: "Neither the original arrest nor subsequent steps politically motivated"

UK Foreign Secretary Robin Cook said that he told Mr Insulza on Friday that "neither the original arrest nor subsequent steps had been politically motivated".

Both ministers expressed a shared commitment to maintain good relations between London and Santiago, and Mr Cook added that he emphasised the UK's strong support for Chilean democracy.

No meeting with Blair

The BBC's David Loyn: Mutual commitment to maintaining relations between Chile and Britain

After the meeting Mr Insulza went to Number 10 Downing Street, the UK Prime Minister's official residence, to deliver a letter of protest, but was not received by Tony Blair.

"We are very much in favour of an international court but we are not in favour of courts of one country judging the events that happen in another," Mr Insulza said.

Deadline extended

Earlier on Friday in London magistrates agreed to the request by the Home Secretary, Jack Straw, to extend the deadline by which he must decide whether to let extradition proceedings go ahead against Pinochet.

David Loyn: Spain will not relish this hot potato

A court hearing next week has been put off until 11 December when Senator Pinochet will have to go to Bow Street Magistrates Court in central London to hear Mr Straw's decision.