WikiLeaks founder Julian Assange’s extradition case started in a London court on Monday.

On the first day of the trial at the Woolwich Court near Belmarsh Prison, where he was detained, Assange spoke only to confirm his name and date of birth.

At the hearing watched by Assange's father, John Shipton, and some of his supporters, the U.S. defense was first heard.

Assange "put lives at risk" by disseminating classified materials through WikiLeaks, said James Lewis, a lawyer representing the U.S. on the first day of extradition hearings.

Lewis also said that journalism cannot be an excuse for breaking the law or criminal activities.

Outside the courthouse, there were also about a hundred protesters supporting Assange.

The first part of the extradition hearings are set to last through Friday, followed by a second phase starting in May. Experts say Assange's extradition case could take up to two years.

If the U.K. court accepts the extradition request from the U.S., where he is accused of espionage, Assange will be able to appeal the case to a higher court and from there the European Court of Human Rights.

If he is extradited to the U.S., Assange will face 18 counts of hacking U.S. government computers and violating espionage law a possible sentence of years in prison.

Last April he was dragged out of Ecuador’s Embassy in London, where he had taken refuge for more than seven years.

British police said he was arrested for skipping his bail in 2012 and on behalf of the U.S. due to the extradition warrant.

Later, he was found guilty of breaking his bail terms in 2012 after failing to surrender to security services by the Westminster Magistrates’ Court and given a 50-week prison term.

Assange was due for a release last September but was held for longer on fears he would flee.