Jammu and Kashmir bus accident
India: 21 killed and 30 injured after bus falls into gorge in Jammu and Kashmir Mukesh Gupta/Reuters file photo

At least 21 people have been killed and 30 injured after a bus fell into a gorge in Udhampur district of India's Jammu and Kashmir.

The passenger bus was ferrying people from Latti belt to Udhampur when it skidded off the main road and plunged into the deep ravine. The death toll is likely to increase as some of the victims are critically injured.

Indian Prime Minister Narendra Modi has expressed grief over the incident and urged authorities to take necessary measures.

"Disturbing news from J-K [Jammu and Kashmir]. Bus accident in Udhampur has saddened me. My thoughts are with families of the deceased. Prayers with the injured. I have asked my ministerial colleague Dr Jitendra Singh to stay in touch with authorities," Modi said in a statement.

The exact number of casualties is unclear as some local reports quoted 25 people are dead. The wounded passengers have been airlifted to the nearby Government Medical College (GMC) hospital in Jammu for treatment.