Indian police have made another arrest after the alleged rape of a teenager by a ruling party politician sparked protests across the country, federal investigators said Sunday.

The case, along with the rape and murder of an eight-year-old girl, has brought Indians onto the streets for mass demonstrations not seen since the rape and murder of a Delhi student in 2012.

The outrage has put pressure on Prime Minister Narendra Modi, whose ruling Bharatiya Janata Party (BJP) is accused of trying to shield its state lawmaker in one case and of defending the accused in the other.

The Central Bureau of Investigation (CBI) has arrested Kuldeep Singh Sengar, a lawmaker from Uttar Pradesh state which is ruled by the Hindu nationalist BJP, for allegedly raping the 17-year-old last year.

Police only brought a case against the powerful politician last week after the young victim attempted to burn herself alive outside the state leader's residence.

The next day, her father, who had been in police custody, died from injuries he sustained in an alleged beating.

“We arrested the second person, a woman named Shashi Singh, in our ongoing investigations of the case on Saturday,” R.K. Gaur, a CBI spokesman, told AFP on Sunday.

Sengar appeared in court the same day and was ordered detained for seven days.

The girl's family — who fought unsuccessfully for nearly a year to get the police to register their case — said Singh had taken their daughter to the state legislator on the pretext of a job.

Singh then allegedly stood guard at the door while Sengar raped the girl, the family's initial complaint to police stated.

Religious tension

Public outrage escalated as details surrounding the brutal rape and murder of an eight-year-old Muslim girl in January in Jammu and Kashmir state made national headlines.

The girl was kidnapped, drugged and repeatedly raped over five days — including inside a Hindu temple — before being strangled and beaten with a rock.

Jammu and Kashmir is India's only Muslim-majority state, but the Jammu region in the south, where the rape and murder took place, is Hindu-dominated.

The case has heightened fears of communal tensions in the region.

Muslim activists have demanded action against what they see as a crime against their community while some right-wing Hindu groups have argued that the accused were unfairly charged.

Eight people have been arrested over the killing, including four police officers and a minor. All are Hindus.

Scenes last week of lawyers trying to stop police from entering court to file charges against the accused sparked nationwide revulsion.

The Supreme Court on Friday warned lawyers in Jammu against any further attempts to obstruct justice, the Press Trust of India reported.

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Two state ministers from Modi's BJP — Choudhary Lal Singh and Chander Prakash Ganga — resigned after attending a controversial rally by local Hindu groups held in defence of the accused.

“They have resigned because of the way the entire thing has been presented across the country. They have been victimised,” Balbir Singh, a spokesman for Choudhary Lal Singh, told AFP.

“All they want is a fair probe and the real criminals to be caught.”

The BJP on Sunday demanded that the main opposition Congress party sack its state leader in Jammu and Kashmir after he suggested the police investigation was politically motivated.

Rampant violence

The crimes have shaken India in a way reminiscent of the fatal gang-rape of a Delhi student on a bus in 2012 that made headlines around the world.

That case unleashed public anger over rampant sexual violence against women in India and the introduction of tough new laws to punish rapists.

But high numbers of assaults persist, with 40,000 rape cases reported every year.

Police in western Gujarat state said on Sunday that a post-mortem examination of a young girl found dumped by a highway near Surat this month indicated she been raped and murdered.

“There were also many minor injury marks over her body. The girl is around 11 years old. We are still trying to establish her identity,” Surat police commissioner Satish Kumar Sharma told AFP.

Protests and vigils were held Sunday in some parts of India including Delhi, the financial capital Mumbai and southern Kerala state.

Modi on Friday promised justice for the victims as anger mounted, while India's women's minister called for the death penalty for child rapists.