Tokyo, March 20 (IANS): Tokyo on Friday commemorated the 20th anniversary of a sarin gas attack by the Aum Shinrikyo, or Supreme Truth, cult in the city's subway, which killed 13 people and injured more than 6,000, Efe news agency reported.

During rush hour on March 20, 1995, five members of the cult opened packages of sarin gas on subway trains in a coordinated attack.

The colourless odourless gas spread across the network within minutes and poisoned about 6,300 people, of whom 13 died and several more were reduced to a vegetative state.

Most victims still suffer physical ailments like loss of vision, chronic fatigue, painful and continuous migraines, and post-traumatic stress.

A minute's silence was observed at Tokyo's Kasumigaseki station, one location severely affected by the attack, while floral offerings were made at five other affected stations in memory of those who lost their lives.

The attack, the worst suffered by Japan since World War II, continues to be marred in controversy even though the perpetrators were caught and convicted.

They all belonged to Supreme Truth cult, a "new age" religious cult founded in 1984 when Shoko Asahara (real name Chizuo Matsumoto) opened a small yoga centre in Tokyo's Shibuya district.

The sect slowly transformed itself into a powerful organisation with the capacity to produce chemical agents and light weapons, and even presented a list of candidates for the 1990 general elections though it did not win any seats.

Before the subway attack in 1995, the sect had been investigated by authorities over responsibility for another sarin attack killing eight in Nagano province, in 1994.

In 1989, it also planned the murder of a lawyer preparing a multi-million dollar suit against the cult.

Following the subway attack in Tokyo, courts tried around 190 cult members and sentenced 13 of them, including Asahara, to death, though none of the executions have been carried out.

Five others were sentenced to life in prison.