An opponent at a candlelit vigil in London

Both the general's opponents and his supporters thought it unlikely the man who for 17 years ruled their country with an iron hand would ever be held to account.

Many say this is a day they thought they would never see.

Viviana Diaz, president of the Families of the Disappeared, said: "For us it's very good news. We had asked British Prime Minister Tony Blair for this, not to let Pinochet leave."

Ms Diaz said she hoped Gen Pinochet would be questioned so he could "answer as to the fate of our loved ones."

Chilean President Eduardo Frei

Isabel Allende, whose father Salvador Allende was killed in 1973 in the coup which brought the military to power, said the arrest was a "unique opportunity for Pinochet to answer for the human rights violations during his regime."

Socialist deputy Fanny Pollarollo said Chile would have to respect the Spanish judges' decision and said: "Pinochet will have to answer for his crimes."

Protest

James Reynolds in Santiago: "The government is in a difficult posiition"

The government of President Eduardo Frei - a long-time political opponent of General Pinochet - is formally protesting at Britain's action. Santiago says the British authorities should have respected the diplomatic immunity which General Pinochet enjoyed as a life senator.

Among the general's supporters there has been a sense of shock and anger.

Gen Pinochet's son, Augusto Pinochet Hiriart, said the arrest was a "transgression against international norms".

He addressed an angry crowd outside the British ambassador's residence in Santiago on Saturday.

Some of the 200-strong crowd threw eggs and stones at the building before moving on to protest at the Spanish embassy.

Chile's Deputy Foreign Minister, Mariano Fernandez, has protested

Senator Julio Lagos denounced the arrest as an "open violation of diplomatic immunity granted by the Chilean government". He said it violated international treaties.

Deputy Pablo Longueira, head of the Independent Democratic Union, called Gen Pinochet's arrest "an insult to all Chileans."

A spokesman for the Pinochet Foundation, retired general Luis Cortes Villa, said the arrest was "an act of cowardice, because he was sleeping when police arrived at his room in the clinic."

Several political parties have called emergency meetings to plan their response.

Amnesty International worker Carlos Salinas: "This is a positive process"

More than 3,000 people are estimated to have been killed by the armed forces and the secret police between 1973 and 1990.

An amnesty law was passed in 1978 by Gen Pinochet which prevented any member of the armed forces - including its commander-in-chief - from being tried for human rights abuses.

Chilean exile Jimmy Bell: "They killed my brother"

Relatives of those who were killed during Gen Pinochet's rule have filed charges against him despite the amnesty law.

He is currently facing 13 different charges in Chile ranging from state terrorism to genocide.