PATNA: A series of small bomb blasts killed six people and injured dozens near a park in eastern India where tens of thousands of people had gathered to hear a speech by the main opposition party’s prime ministerial candidate.

Panic erupted briefly among those who had gathered in the park in the Bihar state capital of Patna after at least five small blasts went off nearby.

Police detained one man for questioning, but did not say whether he was a suspect.

At least 50 people were being treated, according to the head of Patna Medical College hospital, Vimal Karak.

The first blast came from a crude bomb that exploded in a public toilet building on an isolated railway platform, Patna district police chief Manu Maharaj said.

A man who was wounded in the blast later died in a hospital.

Another bomb went off near a movie theater, and two more exploded just outside the park, sending plumes of gray smoke swirling above the crowd.

''All the bombs produced low-intensity blasts,'' Maharaj said.

Bomb disposal and forensic teams found two unexploded bombs around the railway station and were defusing them, railway police superintendent Upendra Kumar Sinha said.

Authorities quickly restored order at the rally, and it went ahead as scheduled with a speech by Narendra Modi, the prime ministerial candidate from the Hindu nationalist Bharatiya Janata Party.

In the first half hour of his speech, however, Modi did not mention the blasts.

His plans to visit Bihar have been controversial since the state’s highest elected leader, Chief Minister Nitish Kumar, severed ties with the Bharatiya Janata Party six months ago to protest Modi’s candidacy. Kumar has questioned Modi’s secular credentials and suggested that he could exacerbate communal tensions between Hindus and Muslims in India.