Japan marked the 25th anniversary Friday of a sarin nerve gas attack in the Tokyo subway system that killed 14 people and injured more than 6,000 others.

A memorial service was held at Kasumigaseki Station, where subway staff wearing face masks to guard against COVID-19 infection observed a moment of silence at 8 a.m., around the time when the attack occurred on March 20, 1995.

The Aum Shinrikyo cult, which carried out the attack, has been disbanded, and its founder Shoko Asahara and senior members were executed in 2018. But successor groups remain active.

On the morning of the attack, the nerve agent was scattered in five subway train cars during rush hour under Asahara’s instructions, leading to scenes of mayhem at multiple stations. Kasumigaseki Station, one of the worst affected, is located in a district where ministries and other government offices are concentrated.

Thirteen victims had died by the end of 1996 while the 14th, Sachiko Asakawa, 56, who had been bedridden with severe brain damage following the sarin attack, died on March 10 this year.

Asahara’s teachings legitimized murder, and in addition to the Tokyo subway attack, cultists sprayed sarin gas in Matsumoto, Nagano Prefecture, in June 1994, killing eight. The attack was meant to have targeted judges before they ruled on a case regarding land purchase by the group.

In November 1989, cult members also murdered lawyer Tsutsumi Sakamoto, who was helping people break away from the cult, along with his wife and their baby son.

A total of 192 people were indicted over the murders and other crimes carried out by the group. During lengthy trials that ended in January 2018, Asahara, 63, whose real name was Chizuo Matsumoto, was convicted of multiple murders, including in the 1995 sarin gas attack, and hanged along with 12 other former senior cult members in July 2018.

Aum Shinrikyo went bankrupt in 1996, but three successor groups — Aleph, Hikari no Wa and a smaller offshoot of Aleph — are now active with some 1,650 followers combined. They have about 30 branches in 15 prefectures and assets totaling ¥1.3 billion ($12 million), according to the Public Security Intelligence Agency.

Aleph is said to keep portraits of Asahara, while Hikari no Wa claims to have abandoned Aum Shinrikyo’s teachings. The agency, however, deems all the successor groups to pose a threat to the public.

Victims had sought a total of ¥3.8 billion in damages, ¥1.5 billion of which has been paid out through sales of Aum Shinrikyo assets.

Aleph, however, stopped paying damages in 2017, leading victims to take legal action to seek the remaining ¥1 billion or so.

In Hokkaido, where the group is active, dozens of people join every year, according to the agency.

To share their experiences with younger people, victims and their families have been holding a gathering each year, but the event that had been scheduled for Saturday has been canceled due to COVID-19 fears.

Shizue Takahashi, 73, lost her husband, Kazumasa, who was deputy stationmaster at Kasumigaseki Station, in the subway attack. She said she hopes to continue her efforts to pass down the events of that day.

“If we forget, it will be repeated,” she said.

Many survivors still suffer from post-traumatic stress disorder, the symptoms of which worsen with age, and have been asking the government to continue providing the support they need.