A Panipat court acquitted suspected Lashkar-e-Taiba (LeT) operative Abdul Kareem on Thursday in a bomb blast case that hit the city in 1997.
Tunda, an LeT bomb expert, was produced in the court in connection with blast in a private bus at a roadways bus stand in the city that left a 10-year-old boy killed and several others injured.
A day before the hearing, the LeT bomb specialist was allegedly attacked in Karnal jail by two inmates.
"The inmates allegedly tried to strangulate him but he was rescued by alert jail staff. He was taken to the local hospital for medical check-up under heavy police security. He is fine," said SP Karnal Pankaj Nain.
"A case under relevant sections of IPC, including murder has been registered against the two accused," a police officer at Karnal Sadar police station said.
A resident of Pikhuwa in Uttar Pradesh's Ghaziabad district, Tunda was arrested by the Delhi Police from Indo-Nepal border in 2013.
The CBI had charged him with organising LeT's major terror attacks outside Jammu and Kashmir. He is accused in over 40 bomb blasts in Mumbai, Hyderabad, Delhi, Rohtak and Jalandhar in which over 20 persons were killed and over 400 injured.