A court in Pakistan has begun the high-profile trial of four Islamic activists accused of kidnapping and murdering American journalist Daniel Pearl.

Ahmed Omar Sheikh, the suspected mastermind of the kidnapping plot, and his three alleged collaborators pleaded not guilty when the judge read out the indictment. Seven other alleged co-conspirators in the case remain at large.

Wall Street Journal reporter Daniel Pearl was abducted in Karachi in January while trying to contact Pakistani religious extremists. His death was confirmed a month later, after the kidnappers released a video tape showing his gruesome murder. Pakistani authorities have yet to find Mr. Pearl's body or the weapon used to kill him.

After Monday's court proceedings, Chief Prosecutor Raja Qureshi gave details to reporters, who are barred from covering the trial. Mr. Qureshi said the trial began with testimony from a taxi driver, identified as Nasir Abbas.

"The nature of the charges framed against accused persons were that of kidnapping for ransom, conspiracy, abetment and murdering Daniel Pearl, which are the acts of terrorism. And based on this, the accused persons pleaded not guilty, whereafter, the court proceeded to record the evidence of the prosecution witness Nasir, who had deposed on oath that, before him, Daniel Pearl was kidnapped by Sheikh Omar."

Defense lawyer Khawaja Naveed told reporters that Sheikh Omar again rejected the authority of the Pakistani court.

"All the accused had pleaded not guilty to the charges, while Omar Sheikh had said that he does not accept this law, and he wants to be tried under the Sharia law."

Under Pakistan's anti-terrorism law, the defendants could be sentenced to death, if they are found guilty. The trial resumes Tuesday, when more prosecution witnesses will be called to record their statements. The law requires the trial be completed in seven days. The four men are being tried within the walls of the central prison in Karachi.