It's been a short journey from cheers to jeers for Narendra Modi.

The Prime Minister's speech at the Babasaheb Bhimrao Ambedkar University in Lucknow today, where he is chief guest at a convocation was greeted with jeers.

A student was escorted out of the auditorium and some protesters have been detained.

The PM is attending several events in Uttar Pradesh today associated with BR Ambedkar, the architect of the Constitution and a Dalit icon, signalling his party's focus on Dalits, who comprise a vital 21-22 per cent of voters in the state, where elections will be held in 2017.

Modi finally broke his silence on the suicide of Dalit research scholar Rohith Vemula in Hyderabad, over which his government has been criticised.

The 26-year-old research student committed suicide on Sunday days after he and four other Dalit students were suspended over clashes with activists of the ABVP, the BJP's students' wing.

The PM said, "Kaaran apni jagah par honge, Rajneeti apni jagah par hogi, lekin sachaayi ye hai ki maa-Bhart ne apna ek laal khoya. Politics aside, a mother has lost her son. I feel her pain. Uske parivar par kya beeti hogi."