The rape victims' family today demanded public hanging of the culprits and refused to take compensation saying they want justice.
"The Chief Minister has decided to recommend a CBI probe into Badaun incident as demanded by family members of the victims," an official statement said in Lucknow.
The development came as the Samajwadi Party government drew flak for its handling of the shocking incident.
Congress Vice President Rahul Gandhi met the victims' family at Katra village and supported their demand for CBI probe.
Three brothers Pappu Yadav, Awadhesh Yadav and Urvesh Yadav have been arrested and booked under sections 302 (murder) and 376 (rape) of IPC while constables Sarvesh Yadav and Chhatrapal Yadav have been booked under Section 120B (criminal conspiracy) of IPC.
Constable Chhatrapal Yadav was arrested late last night and Urvesh Yadav was detained in the wee hours today, Superintendent of Police A K Saxena told PTI.
The FIR was registered against seven persons, including two unnamed men who are absconding.
Katra Sadatganj police outpost in-charge Ram Vilas Yadav was been suspended and services of the two constables have been terminated.
The two girls, who were cousins and aged 14 and 15, went missing from their house on the night of May 27 and their bodies were found hanging from a mango tree in the village in Ushait area on May 28.
The postmortem report of the two girls confirmed that they were raped before murder.
The family of the two victims had also sought a CBI probe, saying they had no faith in local police which was "hand in glove" with the accused.
"The manner in which the entire world saw our innocent girls hanging, we want that in the same manner it should watch the culprits being hanged. They should be hanged publicly," said the father of a victim.
"Had the police acted in time, our daughters would have been alive," he said.
The Opposition slammed the government over the incident with BSP supremo Mayawati demanding a CBI probe. A team of National Commission for Women (NCW) had also faulted the local police.
The Chief Minister had yesterday ordered constitution of fast track court to ensure justice to the victims' family and announced a compensation of Rs five lakh each to them.
The Congress Vice President visited the home of the dalit girls and during the interaction, their family members complained that the police did not act when they approached the local police chowki.
"They have said that the honour of their daughters cannot be brought back with money. They said they want justice and they have no faith in the UP police as their people are involved. They said that the UP police cannot get them justice. I agree with them, there can be no price for a woman's honour.
"I am also in agreement with them on what they have said about the CBI inquiry. CBI inquiry should happen," Rahul said.
The Congress leader also walked to the spot where the victims had been found hanging from a tree.
"Whosoever have committed this crime should know that they cannot do such things in India," Rahul said
Badaun is 300 km from Uttar Pradesh capital Lucknow.