Even as Noida's grisly killings of children have sent shock waves across India, three men allegedly involved in the murder of nine persons, including a woman, in the past one year have been arrested in Hyderabad.

The sensational killings came to light when the bodies of two youths, with their heads smashed, were found near Rajendranagar on Hyderabad's outskirts on January 2.

"The arrest of Ramulu and Pavan in connection with the murder of two youths identified as Dastagir and his cousin Mustafa led to the arrest of another person Venkatesh, a native of Bihar," Assistant Commissioner of Police Mahipal Reddy said on Monday.

The trio helped police identify seven of the nine victims while the remaining two are yet to be identified, he said.

The breakthrough came on January 3 when Dastagir's cousin Mohammed Chand Pasha informed police that he had seen Dastagir going out with Pavan and another person on January 2.

"Pavan was a friend of Dastagir," Reddy said.

Apart from the nine murders, the duo had committed three robberies, he said.

Police, however, denied reports that the alleged killers had sodomised the victims before killing them, saying it had to be investigated.