NEW DELHI — Lying under a striped blanket, her face blank with exhaustion, Shabana Parveen described how she and her family had run for their lives.

Rioters armed with rods and sticks surged into her lane in northeast Delhi last week looking for Muslim homes. Parveen, 26 years old and nine months pregnant, said they broke down the door, punched and beat her, yelled abuse and told her family to get out. Then they destroyed everything inside.

A Hindu neighbor sheltered the family for the night but urged them to flee to a Muslim area as soon as they could. The next day, Parveen’s son was born in a rudimentary clinic filled with people injured or displaced by the riots. “There is nothing left,” she said as her tiny son slept beside her. “If we go back, they will kill us.”

India’s capital is grappling with the aftermath of the worst communal violence in Delhi in decades. More than 45 people, the majority of them Muslims, were killed in the clashes. Hindu mobs swept through lanes targeting Muslim homes and set up roadblocks looking for Muslims to attack. Crowds of Hindus and Muslims threw stones and molotov cocktails.

The violence — which unfolded as President Trump visited the city — marks a major turning point for the nation and for the government of Prime Minister Narendra Modi. Since winning a landslide reelection in May, Modi has pursued his party’s agenda of Hindu primacy in India amid a dramatically slowing economy. In the last six months, he revoked Kashmir’s autonomy, jettisoning decades of policy toward India’s only Muslim-majority state. His government said it would move ahead with the construction of a grand Hindu temple at the site of an illegally razed mosque. And he enacted a controversial law that excludes Muslim migrants from a fast track to citizenship.

Now that agenda has sparked violence along the oldest fault line in India, a Hindu-majority nation created as a secular republic that’s also home to 200 million Muslims. It’s a defining moment for Modi, whose government directly oversees law enforcement in the national capital. The police are accused of doing too little to stop the riots — and, in some cases, joining in.

The violence erupted after a local leader of Modi’s party threatened to clear a protest against the citizenship law. Modi called for calm on Wednesday, but has not mentioned the violence since.

The riots were “not a tactical aberration, some absent-minded lapse of attention,” wrote Pratap Bhanu Mehta, a prominent political scientist. “There is no doubt that the state could have stopped the violence more quickly if it had wanted.”

The consequences for this nation of more than 1.3 billion people are likely to be far-reaching. Saba Naqvi, the author of a book on the recent history of the ruling Bharatiya Janata Party, said Modi and his party are now pursuing a path of “complete polarization” between Hindus and Muslims “because they have no other path to offer.”

A BJP spokesman denied that the party’s policies were polarizing. Muslims are afraid, party spokesman Sudhanshu Trivedi said, because “they have been intimidated by propaganda” spread by opposition parties. He said the BJP’s opponents are fostering a “situation where some unrest can be created in the country so the government gets a bad name at the international level.”

‘We are helpless’

Inside a narrow lane in Mustafabad, a densely packed, predominantly Muslim neighborhood in northeast Delhi, refugees from the violence picked through a mound of donated clothes. Many had fled Shiv Vihar, another riot-hit area about two miles away.

Zaitoon, 40, who goes by one name, half-cried as she rummaged through the items. She said mobs entered her lane shouting “Jai Shri Ram,” or “Victory to Lord Ram,” a slogan favored by Modi’s party, and demanded to know which houses were occupied by Muslims. She said she saw a neighbor set on fire in front of her, an account repeated by other witnesses.

Police arrived Wednesday morning to escort Muslims to safety, she said. They had ten minutes to gather whatever they could carry.

Down a nearby alleyway, plastic chairs were set out to accommodate mourners at the home of two brothers killed in the riots. Aamir Khan, 30, and his brother Hashim, 19, were on their way to Mustafabad on Wednesday night but never arrived. The next day, their brother Sheruddin said, police showed the family photos of the motorcycle they had been riding, now burned, and of their bodies, both with stab wounds.

Their mother sat on the floor in a cramped room, surrounded by women, her face contorted by grief. Aamir’s wife lay next to her, immobile under a brown blanket.

“We are being killed, we are being slaughtered, and they are blaming us,” cried their sister Naghma Alvi, as a neighbor held and rocked her. The brothers were buried on Saturday.

Research on religious violence in India suggests that Modi’s party has little political incentive to prevent such clashes. Researchers at Yale University who examined Hindu-Muslim riots in India from 1962 to 2000 found that when such riots took place, the BJP increased its share of votes in the next state-level election. When state legislators from the opposition Congress Party were elected, the probability of riots in their districts in the following years fell by a third.

When Modi was elected prime minister in 2014, Muslim voters were wary. As chief minister of the state of Gujarat, he presided over the worst outbreak of communal violence in recent Indian history, when more than 1,000 people were killed, mostly Muslims, in three days of riots in 2002. A court-appointed investigation cleared him of any involvement. For years afterward, the United States declined to issue Modi a visa.

Modi’s first term as prime minister saw increasing reports of Muslims being lynched on the suspicion of transporting beef or slaughtering cows, considered sacred by many Hindus.

The passage of the citizenship law in December has stoked fears that the Modi government intends to make Muslims prove their legal status in the country. Trump praised Modi last week for his “incredible” efforts to promote religious freedom.

Political scientist Sudha Pai co-authored a recent study on communal violence in Uttar Pradesh, India’s largest state. She said Indian Muslims have now “reached a point where they realize either they fight back, or something terrible is going to happen.”

In the riots that swept northeastern Delhi, Muslims mobilized to counter perceived threats and clashed with Hindus. A two-lane road separates Muslim-dominated Mustafabad from Hindu-dominated Bhagirathi Vihar. Hindus say a large mob approached from the Muslim side Tuesday night, throwing stones and molotov cocktails and firing guns. “It became difficult to save our lives,” said Yogesh Kumar, 24, an accountant.

“When the fire spreads, everything gets torched,” Sanjay Kumar, 40, said bitterly as he looked around at the destroyed storefronts and burned facades along a lane leading from the main road. He blamed Kapil Mishra, the BJP leader who issued the original threat to protesters who mounted a sit-in.

Mishra “thought he could do the work of the police,” Kumar said. “Why did he step in?”

Area residents said nothing like the violence had ever occurred there before, and relations between the two communities were generally peaceful. Paramilitary troops patrolled the streets and people began to venture out on Friday afternoon, but shops remained shuttered.

The Farukhiya mosque, next to a canal choked with garbage, stood deserted and burned. On Tuesday, Hindus and Muslims threw stones at each other from behind makeshift barriers near the mosque, witnesses said. The pitched battle subsided before the evening prayer. Then the police arrived.

Officers barged into the mosque, sending the women worshipers fleeing. Police beat the imam, the muezzin and an elderly caretaker so badly they were sent to the hospital, according to family members and one of the victims. When Waheeda Khatoon, 30, the muezzin’s wife, finally found him, he was “unrecognizable,” she said.

Khatoon said Muslims had no hope of getting justice. “We are helpless,” she said. “The government and the police belong to them.”

Tania Dutta contributed to this report.