In August, Sheikh Hasina, an ally of Prime Minister Narendra Modi of India, was toppled as Bangladesh’s leader by a popular uprising. She fled to India, and her continued presence there has strained relations between the interim government in Bangladesh and Mr. Modi’s government in New Delhi.

The caretaker administration in Bangladesh, led by the 84-year-old Nobel Prize laureate Muhammad Yunus, has expressed concern that Ms. Hasina is plotting a return to power from India. The interim Bangladeshi leaders have also accused India of exaggerating attacks on Hindus in Bangladesh to score political points at home.

The latest flashpoint was the arrest of Chinmoy Krishna Das, a Hindu monk in Bangladesh, a Muslim-majority country where Hindus make up less than 10 percent of a population of 170 million.

In the past, Mr. Das was associated with an influential global Hindu organization, the International Society of Krishna Consciousness, also known as ISKCON or the Hare Krishna Society.

A court in the Bangladeshi city of Chattogram sent him to pretrial detention under a colonial-era sedition law. His arrest came after a local politician complained that Mr. Das had disrespected the Bangladeshi flag by raising it lower than a saffron-color flag — a symbol of Hinduism — at a rally calling for an end to persecution of Hindus.

The events took a deadly turn when the monk’s supporters surrounded the court. As the security forces struggled to control the situation, a Muslim lawyer was hacked to death, police officials said. The killing was followed by reports of attacks and intimidation in Hindu neighborhoods.

It remains unclear who killed the lawyer. The police have arrested more than 20 people over the violence. The city’s lawyers have gone on strike to protest the killing.

In a statement, India’s Foreign Ministry said it was unfortunate that “a religious leader presenting legitimate demands through peaceful gatherings” was facing legal trouble while extremists behind attacks against minorities, including “desecration of deities and temples,” remained free.

The chapter of Mr. Modi’s Hindu-nationalist Bharatiya Janata Party in the Indian state of West Bengal, which borders Bangladesh, has threatened to blockade the border if the monk is not released.

Bangladesh’s Hindus have long faced prejudice and persecution, and their numbers have shrunk in the face of growing intolerance and rising Islamist militancy.

Ms. Hasina ran a police state that coordinated closely with India and kept a lid on some of the extremist elements who have come out in the open since her fall. But deadly attacks against Hindus took place during her reign as well.

Officials in Mr. Yunus’s interim government have promised equal protection for all Bangladeshis. They have said that India has turned the plight of Bangladesh’s Hindu minority into an emotional political ploy to undermine the movement that toppled New Delhi’s favored leader, Ms. Hasina.

The officials point to an unabated barrage of exaggeration and disinformation emanating from India. Right-wing social media accounts and news media loyal to the Indian government often use terms like genocide to describe the widespread violence that left hundreds of people dead following Ms. Hasina’s ouster, though Hindu leaders in Bangladesh said that only a few were from their community.

In an interview with The New York Times last week, Mr. Yunus acknowledged that the relationship with Bangladesh’s giant neighbor was strained. He listed India’s protection of Ms. Hasina and what he said was “propaganda” from India painting his government as overrun by extremists as factors aggravating relations.

“She is in India. She keeps talking. That’s a bit destabilizing for the whole country,” he said. “And we try to draw attention from the Indian government that this is not fair. You are giving ground for somebody who is thrown away from Bangladesh, and you’re giving his or her a voice.”

Mr. Yunus said that India was “trying to project” an image that Bangladesh under him was becoming “like Afghanistan.” That, he said, was making the already difficult task of charting a new course for his country even harder.

“If you destabilize Bangladesh,” he said, “you destabilize yourself — because these elements of destabilization will spill over everywhere, all around us.”

But analysts said that Mr. Yunus’s government had not helped itself by jailing the monk under a colonial-era law that Ms. Hasina had used to crush dissent.

Some of her worst practices, such as mass cases against opposition members, have continued.

“Terms like ‘sedition’ and ‘conspiracy to destabilize the situation’ are being used, which we have seen before,” said Nur Khan Liton, an adviser to Bangladesh’s Human Rights Support Society, a watchdog.

Sarjis Alam, a leader of the student protests that toppled Ms. Hasina, called for a ban on ISKCON in Bangladesh, labeling it an “extremist organization” that was aligning with India to “plot against us.”

ISKCON’s Bangladesh leaders said the group was law-abiding and expressed sadness at the death of the Muslim lawyer outside the courthouse. They have distanced themselves from Mr. Das after an initial statement of support.

Excerpts: The New York Times