Hyderabad/Chennai: The Andhra Pradesh government on Wednesday justified police firing at red sanders "smugglers" in Chittoor district, in which 20 people, mostly from Tamil Nadu, were killed, saying it was done in self-defence.

"It was an incident where the police had to open fire in self-defence because they were terribly outnumbered," Government's Communication Advisor, Parakala Prabhakar said.

20 people were gunned down on Tuesday in a police operation said to be against Red Sanders smugglers that came under severe attack from the government and political parties in neighbouring Tamil Nadu, which claimed that many victims were labourers from their state.

He said a small combing party of 10-15 personnel were encircled by more than 200 smugglers who were "moving menacingly" towards them.

"In the past, police officials were axed to death, hacked to death. So, in self-defence, police had to open fire," Prabhakar said.

The state had lost six police officers (attacked by red sanders smugglers) while on duty during combing operations in the last few years, he said.

"More than 1000 (red sanders smugglers) are in jail which means wherever possible we have apprehended them and put them in jail. 4500 cases have been registered (against red sanders smugglers) and 6000 vehicles (belonging to smugglers) have been seized," Prabhakar said.

"So, we are not a trigger-happy police force. It was only in self-defence, they had to do."

Asked about reports that the "smugglers" did not have fire-arms, Prabhakar said last time also they had killed police and forest officers with axes and sickles. "So, weapon does not mean fire-arm. They could kill without fire-arm. They did it earlier".

Meanwhile, Tamil Nadu government on Wednesday announced a solatium of Rs 3 lakh each to the next of kin of those from the state gunned down.

Rights groups and political parties in Tamil Nadu had condemned the incident and demanded a full-fledged inquiry.

The National Human Rights Commission had issued a notice to the AP government after one of its members said it involved "serious violation" of human rights of the individuals and the firing could not be justified on the ground of self-defence.

"The Tamil Nadu government has ordered a solatium of Rs 2 lakh to the families of each of those killed yesterday from the Chief Minister's Relief Fund," an official release said.

A team of revenue officials of Tiruvannamalai and Vellore led by Tiruvallur District Collector has been deputed to Tirupati to bring back the bodies. Many of those who died are from Tiruvannamalai and Vellore districts.

Also, a police team headed by IGP Manjunatha has been sent to liaison with Andhra Pradesh police to identify the bodies and conduct post-mortem, the government said. Hearse vans of the State government have also been sent to Andhra Pradesh to bring back the bodies.

AP government officials in Tirupati told reporters that all assistance would be provided to the kith and kin of those killed, including provision of basic amenities. They said they were coordinating with their Tamil Nadu counterparts to ensure bodies are properly identified and taken back.

Centre also sought a report from Andhra Pradesh government about the incident. In a communication, the Home Ministry told the state government to give a detailed report about the incident and send it as early as possible, official sources said.

Andhra Pradesh Chief Minister N Chandrababu Naidu has briefed Home Minister Rajnath Singh about the incident and the action taken by the state government in this regard.

During their telephonic conversation last night, Naidu explained to the Home Minister the circumstances leading to the killing of the 20 red sanders "smugglers" by Andhra Pradesh Police, official sources said on Wednesday.