TOKYO (AFP) - Japan on Wednesday marked the 18th anniversary of a Tokyo subway nerve gas attack with ceremonies and floral tributes to honour the 13 people who lost their lives.

"Eighteen years have passed, but the memory of that day is still vivid," said Ms Shizue Takahashi, whose husband was a subway official assigned to the Kasumigaseki station located in the administrative district of Tokyo.

He was one of two victims at the station that was hit by the worst chemical terror attack in Japan on March 20, 1995, which injured a total of 6,300 people.

"I still feel the shock as if the incident happened yesterday," she said after train staff held a moment of silence at 8am, roughly the hour the attack took place.

The Aum Supreme Truth doomsday cult members released the Nazi-developed sarin gas simultaneously in several packed commuter trains during the morning rush hour.

Thirteen Aum members, including guru Shoko Asahara, are on death row after being convicted over the subway attack.

Asahara, a partially blind preacher who peddled a blend of Buddhist and Hindu dogma mixed with apocalyptic messages, developed an obsession with sarin gas and became paranoid that his enemies would attack him with it.