A Muslim woman has been allegedly raped by 20 men who were angered by her association with India's Hindu nationalist Bharatiya Janata party (BJP), which is the front-runner to grab power in the ongoing parliament elections.

The 32-year-old woman was raped in her home in front of her husband and a teenage daughter by the men -- allegedly all Muslims.

The incident happened on the outskirts of Ranchi city, the capital of the eastern state of Jharkhand.

Police have made one arrest based on the woman's complaint, which identifies seven of the attackers.

"In the FIR [first information report], as many as seven men have been named while others are unidentified," Ranchi police superintendent S K Jha said, according to the Kolkata-based Telegraph newspaper.

BJP leaders have said the woman was targeted as she was a member of the party's minority cell.

"If police fail to arrest all the accused within 48 hours, the BJP will launch a statewide agitation in protest against the incident," said former chief minister Arjun Munda.

The ongoing elections have been wracked by explicit communal polarisation in many parts of India as the BJP has projected firebrand Hindutva champion Narendra Modi as its prime ministerial candidate.

Modi has taken far right positions in the campaign, alarming India's large Muslim minority of more than 150 million.

Modi has been widely accused of abetting the massacre of Muslims in his Gujarat state in 2001 but has not been convicted by any court.

The police report of the case showed the attackers came to the woman's family home after midnight, broke it open and held her husband hostage at gun point. The mob then raped the woman for the next hour and a half, taking turns.

The brutal attack came to an end only when neighbours noticed commotion at the house and appealed for help through a loudspeaker at a nearby mosque.

The alleged rapists fled the scene before crowds gathered at the place, but before fleeing they seized cash and jewellery from the victim's house, the complaint said.

It is not uncommon for Muslims to join the BJP but such cases are few and far between and Muslims holding positions in the party, or in a BJP-led government, is vastly a tokenism.