The men had been in police custody and were shot near the scene of last week's crime, said N Prakash Reddy, a deputy commissioner of police in Shamshabad, near Hyderabad.

"In the morning, at around 6-6:30, our persons have come to reconstruct the scene of crime and the accused have tried to snatch their weapons, and there was a cross-fire. In this, all the four accused have died. Two policemen have been injured," Reddy said.

No details were immediately available about how many police had escorted the four accused and whether they were handcuffed or roped together as is usually the case.

Earlier a local police officer had put the time of the deaths at around 3:30 a.m. (22:00 GMT Thursday). There was no immediate explanation for the discrepancy.

Indian police have frequently been accused of extra-judicial killings, called "encounters", especially in gangland wars in Mumbai and insurrections in Punjab and Kashmir. Top police officers involved in such killings were called "encounter specialists" and were the subject of several movies.

During the past week, thousands of Indians have protested in several cities following the alleged rape and murder of the veterinarian.

The woman, who cannot be named under Indian law, had left home for an appointment on her motor-scooter and later called her sister to say she had a flat tyre. She said a lorry driver had offered to help and that she was waiting near a toll plaza.

Local media said she was taken behind a line of trucks, raped and asphyxiated and her dead body then set alight on the outskirts of Hyderabad. Four men aged between 20 and 28 years were arrested.

Her family welcomed the news of the killings of the alleged perpetrators.

"It has been 10 days to the day my daughter died. I express my gratitude towards the police & govt for this. My daughter’s soul must be at peace now," Reuters partner ANI quoted her father as saying.

Unabated

Crimes against women have been unabated despite tough new laws that were enacted following the 2012 rape and murder of a woman in a Delhi bus that led to an outpouring of anger across the country.

Despite the setting up of fast track courts, cases have moved slowly, for lack of witnesses and the inability of many families to go through the long legal process.

Many Indians applauded the killings on Friday, taking to Twitter to support the police.

"Not sure whether this is right or wrong but feeling very happy..just hope and pray that the ones killed were the real criminals..#hyderabadpolice," wrote one user.

"Quick Justice like this will inculcate fear into the Dirty minds. Our sincere prayers have been answered #hyderabadpolice Hats off," actress Ammu Abhirami posted.

In Uttar Pradesh state, where a rape victim was set ablaze on Thursday while she was on her way to court, opposition politician Mayawati said the police there should take "inspiration" from what happened in Hyderabad.

Indian police registered more than 32,500 cases of rape in 2017, according to the most recent government data. But courts disposed of only about 18,300 cases related to rape that year, leaving more than 127,800 cases pending at the end of 2017.

But some people said the lack of progress in the courts did not mean the police had a free hand to dispense justice.

"This isn't instant justice - this is the absence of justice. We're not going to make women safer by abandoning the rule of law - is that so hard to understand?," said Rukmini S., an Indian columnist in a tweet.

Supreme Court lawyer Vrinda Grover said the police who were involved in Friday's incident should face an inquiry, but in all likelihood would be rewarded with medals. "Killing accused like this is a short cut, but in the long run this won't work, it will carry its own consequences."

REUTERS