Mohammed Ajmal Amir Qasab opened fire on commuters, it is alleged
The leading suspect in last November's deadly attacks in the Indian city of Mumbai (Bombay) has pleaded guilty.
Mohammad Ajmal Amir Qasab stood up before the court to say he admitted his role in the killings.
Mr Qasab, who is a Pakistani, faces 86 charges, including waging war on India, murder and possessing explosives.
It is not clear why he changed his plea after pleading not guilty in May to all charges. More than 170 people died in the attacks, nine of them gunmen.
Prosecutors say Mr Qasab is the sole surviving attacker.
He could face the death penalty if his confession is accepted and judges agree to impose the maximum penalty.
The BBC's Prachi Pinglay, who was in the courtroom in Mumbai, said Mr Qasab appeared calm.
AT THE SCENE
BBC News, Mumbai
Mohammad Ajmal Amir Qasab appeared very calm in court, smiling a number of times as his confession was being recorded. Now Pakistan has accepted he is a Pakistani national he wanted to confess, he told the court.
Mr Qasab spoke lucidly for several hours, giving specific details of names of people he had met, the kind of training he had received and weapons he had used. He talked about his family and named his two brothers and two sisters.
The judge will now meet prosecution and defence teams to hear their views about the change of plea. Legal experts say it is still not clear if the trial is over.
He said there had been no pressure on him to confess and it had been his decision to do so.
"I request the court to accept my plea and pronounce the sentence," he told the judge, smiling.
Prosecutor Ujjwal Nikam said: "We were not expecting this. We were all shocked when he made a plea of guilt.
"It is for the court to decide whether to accept his plea or not. It was all of a sudden. The court is now recording his plea."
Shortly afterwards Mr Nikam told the BBC the confession was "a victory for the prosecution".
During his testimony, the suspect gave details of his journey from Pakistan, the attacks at a historic railway station in Mumbai and the city's Cama hospital.
Mr Qasab's lawyer said he had nothing to do with the confession.
It is not fully clear what prompted Mr Qasab to change his plea.
He said he had done so because Pakistan had finally admitted he was a Pakistani citizen, but that was some time ago.
Police say Mr Qasab confessed before a magistrate to the attacks after his arrest, but he retracted that confession at an early hearing.
His lawyers said then that it had been coerced.
Wept in court
Mohammad Ajmal Amir Qasab, 21, was arrested on the first day of the attacks and has been in Indian custody ever since.
In his initial appearances before the court, Mr Qasab appeared relaxed and smiled and grinned.
But more recently, he broke down and wept in court as a witness recounted the violent events which took place over three days in late November.
The attacks led to a worsening of relationship between India and Pakistan.
India accused Pakistan-based fighters from the banned militant group Lashkar-e-Taiba of carrying out the attacks.
In the immediate aftermath of the killings, Pakistan denied any responsibility, but later admitted the attacks had been partly planned on its soil.
Islamabad also eventually admitted that Mr Qasab was a Pakistani citizen.