Lawyers in Japan have opened their defence of the man accused of masterminding the deadly Sarin nerve gas attacks on Tokyo's underground railway seven years ago.

The attacks killed 12 people and made thousands ill.

Japan's long-running trial

March 95 - Tokyo Sarin attack April 96 - Asahara's trial opened Jan 2002 - Prosecution ended submission 2003 - Defence expected to end submission At least 7 former Aum followers so far sentenced to death

But lawyers acting for Shoko Asahara, the founder of the Aum Shinrikyo, or Supreme Truth Cult, said his doctrine did not justify murder and it had been misunderstood by his disciples.

The trial of Mr Asahara began in 1996, and correspondents say it has come to symbolise the slow pace of Japan's judicial system.

Mr Asahara, 47, whose real name is Chizuo Matsumoto, is accused of ordering the Tokyo attack, as well as other killings, including a June 1994 gassing in the central Japanese city of Matsumoto in which seven people died.

If convicted he could be sentenced to death.

'Misunderstood'

But his defence lawyers claimed in their opening submission on Thursday that as Mr Asahara's sect grew bigger, it became difficult for him to maintain control over all the disciples.

Aum Shinrikyo

Renamed Aleph and claims it is now benign Has about 1,000 lay followers and 650 followers in cult communes Predicted an apocalypse that only cult members would survive Thought to raise most funds from computer software business it runs

"By misunderstanding the teachings of the accused, Matsumoto, some disciples believed it is permissible to deprive people of their lives for their salvation and committed a series of crimes," the defence argued.

His lawyers instead accused Hideo Murai, "science and technology minister" in the cult's self-styled government, and another follower, Yoshihiro Inoue, of planning the subway attacks.

Murai was stabbed to death in front of television cameras in April 1995 by a man outside the cult's Tokyo headquarters. Inoue has been sentenced to life in prison.

Mr Asahara, dressed in a blue sweater and grey trousers, kept his eyes shut as his lawyers spoke, AFP news agency reported.

His defence team is expected to submit "not guilty" pleas on all 13 charges. Their submissions are expected to take about a year.

Aum Shinrikyo has since changed its name to Aleph and renounced violence.

But Japanese security agencies announced on Wednesday that they were renewing their three-year surveillance of the cult as they believe it remains a threat.