NEW DELHI, India (CNN) -- The lone surviving suspect from last year's Mumbai terror strikes Wednesday inadvertently admitted he is 21 years old, contradicting his earlier assertion that he was a juvenile, attorneys said.
Soldiers patrol in Mumbai as the trial gets under way.
The admission means Mohammed Ajmal Kasab can now face trial on charges including waging war against India, murder and attempted murder.
"The cat has come out of the bag," special public prosecutor Ujjwal Nikam remarked as he briefed reporters about Kasab's response to the judge's question about his age.
Defense attorney Abbas Kazmi, however, insisted that Kasab gave his age as 21 because the court believed he was not a juvenile. His client's real age, Kazmi claimed, was 17-and-a-half years.
The court, which had already rejected his underage claims, fixed 86 charges against Kasab, a Pakistani national, and two Indian men accused of assisting the November attacks in Mumbai, Nikam said.
All three suspects have pleaded not guilty. Nikam told CNN he would now present evidence against the suspects.
Earlier, medical tests on Kasab had shown that he was not a juvenile so should be tried as an adult, Nikam said. A panel of four doctors carried out dental and bone tests and determined that he was older than 20.
Kasab is charged with 12 criminal counts including murder, attempted murder and waging war against India. He has recanted, saying he confessed under duress.
He was caught on surveillance camera holding a gun as he stalked and killed people inside Mumbai's main train station in November, police said. Kasab is also accused of shooting people at Mumbai's Cama hospital.
Kasab is one of 10 Pakistani nationals who police said unleashed terror on Mumbai, India's financial capital, for four days and three nights.
Police said the gunmen killed more than 160 people as they took over three luxury hotels and a Jewish center, and shot up several other places, including a popular restaurant.
The attack was an effort to capture Kashmir, prosecutors said. A dispute over whether India or Pakistan owns the territory has led to wars between the two countries.