NAIROBI, Kenya — One Ethiopian journalist was taken away by police officers as his distraught 10-year-old daughter clung to him. Another fled the country after she said armed men ransacked her home and threatened to kill her.

And a foreign reporter working for The New York Times had his press credentials revoked, days after he interviewed victims of sexual assault and terrified residents in the conflict-torn Tigray region of northern Ethiopia.

Six months into the war in Tigray, where thousands have died amid reports of widespread human rights abuses, Prime Minister Abiy Ahmed of Ethiopia has sought to quell critical coverage of the conflict with a campaign of arrests, intimidation and obstruction targeting the independent news media, according to human rights campaigners and media freedom organizations.

Mr. Abiy, who was awarded the Nobel Peace Prize in 2019, is contending with an election scheduled for June 5 that is expected to cement his hold on power. But rights groups describe a climate of fear and repression that has eroded Ethiopia’s already-tenuous press freedoms and could undermine confidence in the outcome of the vote.

When Mr. Abiy came to power, Ethiopia was among the most repressive countries for journalists in Africa, and he quickly won global praise for a series of sweeping reforms. Journalists were freed from incarceration, hundreds of websites were unblocked and Ethiopia hosted the World Press Freedom Day celebrations for the first time.

Social media usage exploded. And for the first time in 14 years, Ethiopia did not have any journalists in prison.

When Mr. Abiy collected his Nobel Peace Prize in Norway in December 2019, he broke with tradition by not taking questions from the press. In his acceptance speech, he accused social media platforms of sowing discord in Ethiopia.

After Mr. Abiy began a military operation in Tigray on Nov. 4, hoping to oust a regional ruling party that had challenged his authority, press freedoms deteriorated further.

Within hours, the internet in Tigray was shut down and journalists were blocked from entering the region. Later, the authorities detained Ethiopians working in Tigray for international news outlets including the BBC, Agence-France Press, the Financial Times and The New York Times.

Since November, the Committee to Protect Journalists has documented the arrests of at least 10 journalists and media workers who were held for periods from a few days to two months related to their coverage of the conflict in Tigray.

Last week, government officials confirmed that they had revoked the accreditation of Simon Marks, an Irish reporter based in Ethiopia working for The New York Times.

In a war that has already caused thousands of deaths, displaced at least two million people and led to charges of ethnic cleansing, news media coverage has become a “very sensitive” topic for the government, said Befeqadu Hailu, an Ethiopian journalist imprisoned for 18 months by the previous regime.

In the early days of the fight, at least six Ethiopian reporters working for local media in Tigray were arrested. Later, the authorities turned against Ethiopians working with international news outlets. In December, Kumerra Gemechu, a cameraman with Reuters, was detained and held without charge for 12 days before being released.

In January, human rights groups accused the security forces of killing Dawit Kebede, a reporter who was shot dead in the Tigrayan capital of Mekelle, ostensibly for flouting the curfew.

In February, armed men ransacked the home in Addis Ababa of Lucy Kassa, a freelance reporter for the Los Angeles Times and other outlets. In an interview, Ms. Lucy, who has since fled to another country, said the men appeared to be government agents, knew what story she was working on and warned her to stop. They confiscated a laptop and flash drive that she said contained evidence that soldiers from the neighboring country of Eritrea were fighting in Tigray, though Ethiopia had insisted at the time that this was untrue.

The government said in a statement at the time that Ms. Lucy had not legally registered as a journalist.

In March, the Ethiopian government permitted several news organizations to travel to Mekelle, but then detained the Ethiopians working for them for several days.

Mr. Marks, who works for The Times and other publications, has reported from Ethiopia since 2019. In a letter revoking his accreditation on March 4, the Ethiopian Broadcasting Authority accused him of “fake news” and what it called “unbalanced” reporting about the conflict in Tigray.

A day earlier, Mr. Marks had returned to Addis Ababa from Tigray, where he interviewed civilians who described atrocities by Ethiopian and Eritrean soldiers, and women who said they suffered horrendous sexual assaults.

That reporting was the basis of two stories published by The Times in the following weeks.

Last week, after appeals by The Times were declined, the head of the Ethiopian Broadcasting Authority confirmed Mr. Marks’s accreditation had been canceled at least until October. Officials told Mr. Marks that The Times’ coverage of Ethiopia had “caused huge diplomatic pressure” and that senior government officials had authorized the decision to cancel his papers.

“It is deeply disappointing that a Nobel Peace Prize recipient would try to silence an independent press,” said Michael Slackman, The Times’s assistant managing editor for international. “We encourage the government to rethink this authoritarian approach and instead work to foster a robust exchange of information. It can start by reissuing Mr. Marks’s credentials and freeing any journalist being detained.”

The next test of Ethiopia’s openness is likely to be the June 5 election, the first for Mr. Abiy since being appointed prime minister in 2018.

Billene Seyoum, a spokeswoman for Mr. Abiy, referred questions about Mr. Marks to the Ethiopian Broadcasting Authority.

In a telephone interview, Yonatan Tesfaye, the deputy head of the broadcast authority, confirmed that Mr. Marks’s credentials had been revoked. He added that while they did consult other government institutions, including law enforcement, the Ethiopian Broadcasting Authority made the decision independently.

He said the authority was also examining the work of Ethiopian journalists for potential violations of Ethiopian law.

“We want the media to take the context we are in and we want them to operate respecting the rule of law that the country has,” he said.