Schools and businesses shut across Indian-occupied Kashmir on Wednesday as protests grew over the death in police custody of a young school teacher that sparked outrage across the restive territory.

Indian police bundled Rizwan Asad Pandit from his home in a late-night raid on Sunday to a detention centre in the main city of Srinagar, where he died in the early hours of Tuesday.

No official explanation has been offered for his death. Police say Rizwan — who spent his 29th birthday in custody — was taken “in pursuance of a terror case investigation”.

He was a campaigner for Jamaat-e-Islami Kashmir, which was outlawed by New Delhi this month.

Authorities launched a sweeping crackdown that has seen hundreds arrested since. But his family said Rizwan had no links to militancy and was murdered.

“He has been murdered in cold blood, and now they are telling lies about his death. How could that be? He has been tortured to death,” Rizwan's brother Zulqarnain Pandit told local newspaper Kashmir Reader.

News of his death spread quickly in occupied Kashmir, where popular anger against Indian occupation in the Muslim-majority region often erupts into violent clashes between civilians and Indian forces.

Local authorities have ordered an inquiry into Rizwan's death but police have not registered an official investigation yet.

Shops and schools were shut in Srinagar and large parts of occupied Kashmir in protest after three major Kashmiri groups in the region called for a strike.

Rights groups, including the United Nations rights office, have accused Indian forces of acting with “virtual immunity” in occupied Kashmir, protected by laws that shield soldiers from prosecution. There have been more than 100 official inquiries into civilian deaths in occupied Kashmir since 2008 but none has resulted in convictions, said Khurram Parvez, a high-profile local activist.

“This absolute impunity completely scuttles justice,” he said.

At the height of major demonstrations against Indian rule in 2016, another teacher died in military custody, fuelling popular anger. The soldiers accused of murdering the man were never prosecuted.