Lagos, Nigeria (CNN) Nigerian activist and journalist Omoyele Sowore was dramatically re-arrested Friday just hours after being freed on bail, in a case that has raised questions over free speech in the country.

Sowore, who is the publisher of US-based Sahara Reporters newsite and ran for president in February's general elections, was detained after calling for a nationwide demonstration against President Muhammadu Buhari. He was charged with treason , money laundering and cyberstalking the President, but denies all charges.

Sowore is being held by Nigeria's intelligence agency, the Department of State Security (DSS), since his arrest on August 3 -- despite two court orders granting him bail.

The journalist was released briefly on Thursday after a federal court gave the intelligence agency a 24-hour ultimatum to release Sowore pending his trial.

But DSS officials, wielding guns, stormed a federal high court in the capital Abuja on Friday where the journalist is on trial for treason and attempted to "forcefully arrest" him, his wife Ope Sowore and other witnesses told CNN.

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