India's parliament was in uproar Wednesday after four men belonging to the low-caste Dalit community were beaten while trying to skin a dead cow in western India.

Lawmakers from the opposition parties shouted slogans while accusing Prime Minister Narendra Modi's government of failing to protect the Dalits, who belong to the lowest rung of Hinduism's caste hierarchy.

Videos of the four being stripped and beaten with sticks by men claiming to be cow protectors in Gujarat state last week have gone viral and have sparked protests by Dalit groups across the state.

Hindus consider cows to be sacred and the slaughter of cows is banned in many parts of India. Slaughtering a cow carries a punishment of up to seven years in jail.

Attacks against Muslims and Dalits accused of eating or smuggling beef have risen since Modi's Hindu-nationalist party came to power two years ago.

Vigilante groups comprising mostly members of Hindu nationalist organizations have become active in small towns and cities across India over the past year. Last year, a Muslim man was lynched by a mob in northern Uttar Pradesh state over charges that his family had eaten beef for dinner.

Dalits usually carry out undesirable tasks such as skinning dead animals, and many work in tanneries and in the leather industry.

The four men who were attacked by vigilantes in Una town in Gujarat last week worked in a tannery. In the video, they were seen pleading that they were tannery workers who were only skinning the dead animal.

Gujarat's top elected official, Chief Minister Anandiben Patel, on Tuesday promised that her government would take strict action against those involved in the attack.

Eight men have been arrested, she said. Four police who failed to take action have been suspended for dereliction of duty, she said.

Several towns in Gujarat have been rocked by protests since last week's beating incident, and at least seven Dalit men have attempted suicide, lawmakers told Parliament on Wednesday.

"Dalits are being oppressed in Gujarat and we have to raise our voices to get the government to act," said Derek O'Brien, a lawmaker from West Bengal state. "This is an organized crime that is happening in Gujarat."