NEW DELHI (AP) — India’s Supreme Court on Monday denied bail to two Muslim student activists who have spent years in detention without trial over a conspiracy case linked to one of the country’s deadliest outbreaks of religious violence.

Umar Khalid and Sharjeel Imam were arrested five years ago under India’s harsh state security law and accused of conspiring to incite the communal violence that swept parts of Delhi in February 2020. The riots left 53 people dead, most of them Muslims, and took place amid massive months-long protests against a controversial 2019 citizenship law that critics said discriminated against Muslims.

While bail was granted to the other five accused in the same case, the court noted that Khalid and Imam had a “central role in the conspiracy.” It also said that the delay in their trial was not a sufficient ground for granting them bail.

“Umar Khalid and Sharjeel Imam stand on a qualitatively different footing as compared to other accused,” the Supreme Court said in its verdict, according to Bar and Bench, a legal news website.

The two student activists were a leading voice in nationwide protests against the citizenship law, which marked one of the most significant challenges to Prime Minister Narendra Modi’s Hindu nationalist government. Their detention has been widely seen as emblematic of a broader crackdown on dissent under Modi, drawing criticism from rights groups over the use of anti-terror laws against activists and student leaders.

In the months following the riots, police charged several activists and organizers, including Khalid and Imam, under the Unlawful Activities (Prevention) Act, that in the past was used only to quell violent insurgencies but under Modi has been largely used to silence political opposition. Activists and other dissenters targeted under the law can be held in pretrial detention almost indefinitely, often resulting in years of detention until the completion of trial.

Prosecutors representing the Delhi police had strongly opposed Khalid and Imam’s bail request, arguing that the violence was not a spontaneous outbreak but a deliberate plot intended to tarnish India’s global image, and that they made provocative speeches and instigated violence. Khalid and Imam’s lawyers argue that there is no evidence linking them to the violence and deny the charges against them.

Dozens of other Muslims were also charged in similar cases related to the riots and held under prolonged detention. Some of those cases later unraveled because police were unable to provide evidence linking many detainees to the riots.

Last week, eight U.S. lawmakers wrote to India’s ambassador in Washington expressing concern over Khalid’s prolonged pretrial detention. They urged Indian authorities to grant him a fair and timely trial.

International human rights groups have also repeatedly urged Khalid and Imam’s release, saying their detention suppresses dissent and breaches fundamental legal protections.

Amnesty International in a statement last year said Khalid’s “imprisonment without trial exemplifies derailment of justice” and is “emblematic of a broader pattern of repression faced by those who dare to exercise their rights to freedom of expression.”