MUMBAI - The trial of the only Islamist militant suspect captured during November's Mumbai attacks in India opened in disarray Wednesday with the judge dismissing the defence lawyer.

Moments after the trial started, the packed courtroom was told there could be a conflict of interest as the defence lawyer for Mohammed Ajmal Kasab may have links to a potential witness for the prosecution.

"It does not appear appropriate. In my opinion there can't be any other option left to the court," judge M.L. Tahaliyani said, adjourning proceedings to later in the day.

The 21-year-old Kasab, said to belong to the banned Pakistan-based Islamist group Lashkar-e-Taiba (LeT), faces a string of charges including "waging war" on India, murder, attempted murder and kidnapping.

He faces the death penalty if convicted of taking part in the November 2008 rampage of killing in India's financial capital, which saw 10 gunmen land in the city by boat and murder more than 160 people.

A further 300 others were wounded in the 60-hour-long attacks, which saw a packed railway station, two luxury hotels, a trendy cafe and Jewish centre left littered with bodies.

Legal proceedings have already been dogged by the issue of who should defend him.

Last year, the Mumbai Metropolitan Magistrate Court's Bar Association resolved not to represent him, while the Hindu nationalist Shiv Sena party called for Kasab to be executed without trial outside the railway station.

Anjali Waghmare, the lawyer who was dismissed, was also denounced for eventually taking on the case and was attacked by irate Hindu radicals. She has since been given the highest level of police protection.

The brief court session Wednesday saw Kasab make his first public appearance since his arrest.

The courtroom, last used to try suspects over the deadly 1993 bomb blasts in the city, has been reinforced, while a bomb-proof tunnel has reportedly been built from Kasab's cell after he received death threats.

Traffic was banned from around the prison for the duration of the trial, which is expected to last up to six months and may hear testimony from as many as 2,000 witnesses.

Kasab appeared unable to follow the proceedings, which were conducted in English and Hindi, an AFP reporter in the courtroom said.

The defendant, the nine dead gunmen and 35 other LeT "terrorists" wanted over the attacks carried out a "heinous criminal conspiracy" against the city and people of Mumbai and India, according to the charge sheet.

Two other men are also on trial. Indian nationals Fahim Ansari, 35, and Sabauddin Ahmed, 24, are accused of providing the group with logistical support before the attacks.

Prosecutors say they have evidence that "undoubtedly and conclusively" links the attacks to India's arch-rival Pakistan, including mobile and satellite phone communication between the gunmen and their LeT "handlers."

Kasab's DNA and fingerprints were found on items retrieved from the hijacked Indian fishing trawler the gunmen used to get to the Mumbai coast, it is alleged.

There is CCTV and other footage of him at Mumbai's main railway station, where more than 50 people died after two gunmen opened fire with AK-47 assault rifles and threw grenades.

Thirty eyewitnesses also picked him out in identification parades, it added.