Indian Prime Minister Narendra Modi’s party lost an election in a key state he visited frequently before the recent virus surge forced him off the campaign trail, adding to growing signs of a backlash over his government’s handling of the world’s worst Covid-19 outbreak.

In West Bengal, incumbent Chief Minister Mamata Banerjee’s All India Trinamool Congress won around 72% of 292 seats up for grabs, while Modi’s Bharatiya Janata Party took 77, according to results posted on the Election Commission of India on Monday. Last month, the prime minister predicted his party would win more than 200 seats in the state, which held voting over eight phases starting on March 27.

Supporters of the All India Trinamool Congress celebrate the party’s lead, in Siliguri on May 2.

Photographer: Diptendu Dutta/AFP/Getty Images

Modi’s opponents won in the southern states of Tamil Nadu and Kerala, while his party kept power in the northeastern state of Assam and gained the federally-controlled territory of Puducherry, where it contested in alliance with a regional party. He conceded West Bengal in a series of posts on Twitter, congratulating Banerjee while also noting the BJP made gains in the state.

India’s S&P BSE Sensex fell 1.1% to 48,248.64 at 9:25 a.m. in Mumbai, on course for a one-week low. The benchmark gauge gained 1% so far this year.

The focus now will be how well policy makers are able to minimize the socio-economic cost of Covid-19, said Madhavi Arora, an economist at Emkay Global Financial Services Ltd. “It could also have implications for 2022 state elections,” Arora said, including the major BJP-held states of Uttar Pradesh and Gujarat.

Grim scenes of overcrowded crematoriums and pleas for oxygen have overshadowed the election in recent weeks, with Modi coming under fire for campaigning in front of huge crowds as infections were spiraling. Daily deaths in India hit a record 3,689 on Sunday, while the number of cases slowed slightly after the country became the first to cross the mark of 400,000 cases in a day.

“As three strongly anti-BJP regional leaders have emerged victorious, they are likely to be the nucleus of the opposition challenge to Modi in the months ahead as he battles the backlash to his mismanagement of the Covid crisis,” said Arati Jerath, a New Delhi-based author and political analyst who has written about Indian politics for nearly three decades. The results weaken the government and indicate there are “huge political and constitutional challenges ahead for Modi.”

Kolkata North Goes to the Polls in West Bengal Election Amid Virus Fears

People wait in line at a polling station in Kolkata, on April 29.

Photographer: Arko Datto/Bloomberg

The vote count on Sunday came a day after 12 patients, including a senior doctor, died when a hospital in the capital New Delhi ran out of oxygen after sending out desperate calls for help — the third such incident in the last 10 days. Shortages of beds, oxygen and medical supplies at major hospitals during the latest virus wave have shown a spotlight on India’s underfunded health system.

“We have been raising this kind of alarm to the government, because it is an ongoing situation that is worsening everyday,” Sudhanshu Bankata, the executive director of the Batra Hospital, said by phone.

Delhi Chief Minister Arvind Kejriwal said Saturday his administration had told both the courts and the federal government that his state had only been allocated 490 metric tonnes of oxygen per day, about half of what it needs.