When Bangladeshi blogger and social activist Ashif Entaz Rabi hosted a TV talk show about a slaying of a publisher by Islamic extremists, he faced a torrent of threatening phone calls. He says young men with earpieces started loitering outside his workplace, and a militant website urged followers to "send this Ashif to Allah."

But Bangladeshi authorities told him they couldn't protect him, saying he'd need the kind of security usually reserved for the prime minister to keep him safe. Instead, they told him to take care of himself, and write something good about Islam and the government.

Rabi, 37, is in Washington at the invitation of a human rights group, calling attention to the dozens of writers and bloggers who fear they could be the next victim of a wave of savage attacks on liberals and religious minorities in Bangladesh. The violence has had a chilling effect on freedom of expression in the traditionally moderate Muslim nation.

Tuesday marks World Press Freedom Day, and a coalition of rights groups are calling for a U.N.-backed inquiry into the killings because Bangladesh's government has failed to address the situation. They say "an atmosphere of complete impunity" in the South Asian nation is emboldening the killers. Since the beginning of 2015, at least nine intellectuals, academics, writers, bloggers, and activists have been hacked to death in targeted assassinations.

Rabi attended the annual White House Correspondents' Association dinner at the weekend, and is due to meet Tuesday with a top State Department envoy on human rights, Tom Malinowski, to discuss the deteriorating climate of tolerance in Bangladesh. He'll also be hoping to find a way to secure sanctuary in the U.S. for himself and his immediate family.

"It's better that the international community do something rather than just make statements. It's no use just issuing letters, as the prime minister (of Bangladesh) does not care," Rabi told The Associated Press on Monday.

Secretary of State John Kerry called Bangladeshi Prime Minister Sheikh Hasina on Thursday, urging Bangladesh to protect those at risk. He also offered U.S. support for the investigation into the slaying last week of Xulhaz Mannan, a U.S. Agency for International Development employee and gay rights activist.

Since December, the U.S. has said it is considering providing temporary sanctuary to some individuals at immediate risk, although it remains unclear whether that will happen.

A broader concern for Washington is that transnational jihadist groups could gain a foothold in Bangladesh despite the nation's traditions of secularism, free speech and respect for its Christian and Hindu minorities.

Nearly all the attacks have been claimed by groups like the so-called Islamic State and various affiliates of al-Qaida. The government, however, has denied that these groups have a presence in Bangladesh, and has blamed the violence on the political opposition.

While there have been some arrests — mostly of low-level operatives — there have been no prosecutions so far and authorities have struggled to make any headway in naming those planning the attacks.

Rights groups charge that top officials have instead condemned the targeted individuals for their writings.

"When a government willfully shirks its responsibility to protect its citizens and hold accountable those guilty of such brutal attacks, the international community has to step in," said Suzanne Nossel, a former U.S. official and executive director of PEN American Center, which is among 16 international rights group calling on governments to support the establishment of a Commission of Inquiry by the United Nations Human Rights Council.

It's unclear if there would be adequate international support for such action, which would require a government to propose it, and a majority at the 47-member council to back it. Such commissions have been established to investigate mass rights abuses, as in North Korea, Syria and Libya, rather than the kind of targeted killings happening in Bangladesh.

Bangladesh's constitution enshrines free speech, but Rabi, who started his career as an editor of a satirical cartoon magazine, is no stranger to threats and intimidation.

When he began blogging in 2008, he said it provided a new way to highlight abuses of power that mainstream media shied away from. He wrote and organized demonstrations about the plight of Bangladeshi migrant laborers on death row in Saudi Arabia, safety failings in the garment industry, and even about the risk of an Islamic militant dying in police custody.

He said he has toned down his writings and activism since 2013, when the spate of slayings began, but after he hosted a show about the killing of a publisher of secular books in October, it attracted a rash of death threats. He said police told him to register a formal complaint about the threats but offered him no protection.