By Arpan Chaturvedi

NEW DELHI (Reuters) - Thousands of lawyers in India's capital protested on Monday against an overhaul in criminal legislation by staying away from work and boycotting court hearings, as opposition mounted to the changes.

Many have been angered by new laws that came in on July 1 expanding police powers to keep people in pre-trial detention and requiring judges to issue written rulings within 45 days of the end of a trial.

Prime Minister Narendra Modi's government has defended the changes - which also include the death sentence for gang rape of women under 18 - saying they are "victim-centric", modernise the system and "end the endless wait for justice".

But lawyers' bodies, opposition parties and activists have called for a pause, saying the changes will give excessive powers to the police and pile pressure onto an already overburdened justice system as lawyers try to interpret and challenge the new legal provisions.

Lawyers in seven district courts around New Delhi took part in the strike on Monday, N.C. Sharma, the spokesperson of the All District Courts Bar Associations of Delhi, said.

"Lawyers are protesting because the changes will create confusion," he added.

New Delhi's Patiala House district court was much quieter than usual on Monday when Reuters visited. One court official, speaking on condition of anonymity, said many cases were not argued and lawyers sought adjournments.

The Supreme Court of India and the High Court continued to operate normally.

(Editing by Aditya Kalra; Editing by Andrew Heavens)