"Deeply pained by the loss of lives caused by a bus mishap in Meghalaya's East Jaintia Hills District," Modi tweeted.
"My thoughts and prayers are with the families of the deceased in this hour of grief," he said in another tweet.
A bus, on its way from Silchar to Guwahati in Assam, skidded off the road and fell into a deep gorge near Sonapur this morning, killing at least 30 people and injuring 11.