New Delhi/Bangalore, Sep 5 - India Saturday strongly condemned the attack by Nepali Maoists on two Indian priests at the Pashupatinath temple in Kathmandu calling it an 'unprovoked and criminal act of violence' and conveyed its concerns to the Nepali government over the 'unfortunate' incident.

Kathmandu, on its part, has informed New Delhi that over 25 people, including the ringleader behind Friday's attack, has been arrested by Nepali police.

The attack on the two newly appointed Indian priests has caused deep anguish and serious concern in India, external affairs ministry spokesperson Vishnu Prakash said in a statement in New Delhi.

'The matter was immediately taken up through our embassy in Kathmandu at the highest levels in the government of Nepal and our concerns conveyed,' he said.

'We strongly believe that this unprovoked and criminal act of violence goes against the grain of the civilisational ties of friendship that have existed since time immemorial between the peoples of Nepal and India,' Prakash said.

The two newly-appointed Indian priests, Girish Bhatt and Raghavendra Bhatt, were attacked by 10-12 Maoists who tore their clothes and cut their sacred thread at the Pashupatinath temple Friday.

The issue of Indian priests officiating at the temple has been simmering for some time.

The two priests had arrived from Karnataka this month to continue the nearly 800-year-old tradition at the revered temple of employing priests only from southern India.

Earlier in the day, External Affairs Minister S.M. Krishna reacted to the incident in Bangalore. 'We are aware of the attack by Maoists on the priests and we are in touch with the government of Nepal,' he said.

'The information we have received is that security has been increased around the temple and priests who were attacked have been provided ample security,' Krishna told reporters.