Jerusalem Police detained on Thursday two activists involved in an upcoming protest for the legalization of marijuana.

Amos Dov Silver and Ofer Bar-Tov are two of the organizers of protest smoke-a-thon "The Big Bong Night," planned for Saturday night in front of the Knesset. More than 5,000 people confirmed they were attending on the event's Facebook page.

A Jerusalem court extended their detention Friday, after they refused release on condition that they refrain from attending Saturday's event. 

Police asked the court to release the activists to house arrest on suspicion of sedition, conspiracy to commit a misdemeanor and advocating the formation of an illegal association. The police also wanted to get them far from Jerusalem for 90 days. The judge denied the police request for house arrest, but said that the two would not be allowed to access the site of the planned protest until Monday.

The pair rejected these conditions, however. They decided to remain in detention on the grounds that the decision denies them their freedom of expression.

Their lawyer Yael Totchani said that she would appeal the district court, describing their detention as "a violation of freedom of expression which is a basic right." She also said the pair had been "silenced."

Jerusalem police said in response that Silver was "detained for questioning. At the end of the questioning the police requested to release him under certain conditions, as he refused these conditions, he was jailed."

Marijuana legalization activists in Israel are furious, and say the arrests are an attempt by the police to stop Saturday's event. Silver, known as "Green Amos," is being described as the "first political prisoner of the struggle for legalization."

This past week, Silver said on his Facebook page that he was approached twice by Jerusalem police to come in for questioning while he was handing out fliers for an event. He said the police would not tell him what they wanted to question him about.

The aim of "The Big Bong Night," set for the night before the international cannabis day on April 20, is to organize a protest that challenges the law. On their Facebook page, the organizers write, "Get out of our bodies!! You will have to arrest us all together, because if you arrest only one of us we will inquire why everybody isn't being arrested, and only that one person is. And nobody in their right mind will arrest all of us. Either with a license or without one, either smoking for healing an illness or to maintain general health, and also supporters of freedom from where they may come – everyone is invited.The prohibition and the drought can end in a moment, come be a part of history."

Jonathan Spiegelman, one of the protest's organizers said that, "No arrest will stop us, we are free people, who live in a country that says it is free and you can't shut us up."