Condemning the attack on railway board examination centres in suburban Mumbai by Maharashtra Navnirman Sena activists, Railway Minister Lalu Prasad Yadav [Images] on Sunday demanded a ban on the outfit, saying its chief Raj Thackeray was a "mental case".

"I strongly condemn the incident. There should be an inquiry into the attack. There should be strong action against that party. MNS should be banned," the minister told reporters in Delhi [Images].

His comments came as a response to the attack on 13 railway board examination centres in suburban Mumbai by MNS activists who protested "inadequate representation" to locals and chased away candidates from north India.

Lalu Prasad said the directions of the Supreme Court or any other courts did not have any impact on the MNS leader.

"We can see such incidents when the elections are near," he said.

The minister said he had spoken to Maharashtra Chief Minister Vilasrao Deshmukh who assured him of a proper inquiry into the incident.