Two people in custody have confessed to attacking two teenage girls who were found dead, hanging from a tree, after being raped in northern India, police have told the AP news agency.

Another suspect is in custody and police continue to search for two other suspects on Sunday, the fourth day of the investigation , police officer Atul Saxena told AP.

When questioned by police, the men admitted they had attacked the girls, Saxena told the news agency.

The girls, 14 and 15, were found hanging from a tree near the village of Katra, in Uttar Pradesh, on Tuesday. Initially police believed the girls had hanged themselves, but later said they suspected they had been killed by their attackers.

The three suspects arrested so far are cousins in their 20s. Rape that involves the death of the victim is punishable by the death penalty in India.

On Saturday, the office of the chief minister of Uttar Pradesh state, Akhilesh Yadav, said that it would recommend a probe by the federal agency, the Central Bureau of Investigation.

"The chief minister has decided to recommend a CBI probe ... as demanded by family members of the victims demanded," an official release said.

Saxena said that police were preparing identity sketches of the two suspects at large, based on descriptions provided by those arrested near where the girls were found in the village of Katra, about 300km from the provincial capital, Lucknow.

Residents worried

The two girls disappeared on Tuesday night after going into fields to relieve themselves as their home had no sanitation.

Some of the residents of Katra were worried that such crimes would be repeated as it is common for women to go into the fields alone to go to the toilet.

"We have to go out in the open to go to the toilet every time. We have to work in the fields alone, go outside with our children alone. Today these girls were found hanging, tomorrow it might happen to us," Purnima told Reuters.

Authorities also have arrested two police officers and suspended another two for failing to investigate when the father of one of the teenagers reported the girls missing.

Federal authorities are expected to take over investigation into the crime this week, Saxena said.

Source: Agencies