MANILA- Rappler chief Maria Ressa, whose news site has clashed with President Rodrigo Duterte, walked out of overnight detention on Thursday after posting bail of P100,000 for cyber libel, a charge that press freedom advocates branded an act of "persecution."

Ressa, who was named a Time Magazine "Person of the Year" in 2018 for her journalism, was arrested Wednesday over a 2012 Rappler article which its subject, businessman Wilfredo Keng, claimed was "clearly defamatory."

A Pasay court earlier refused to accept the veteran journalist's bail, forcing Ressa to spend the night at the National Bureau of Investigation headquarters in Manila.

Rappler chief Maria Ressa stressed that her arrest is an "abuse of power and weaponization of the law" and appealed to her fellow journalists not to be silent "even if you're next." #ANCRecap pic.twitter.com/FbOuY5rKVX

— ABS-CBN News Channel (@ANCALERTS) February 14, 2019

Ressa said her ordeal was an example of the government's "abuse of power and weaponization of the law."

"This is not just about me, and it is not just about Rappler. The message the government is sending is very clear and someone actually told our reporter this: be silent," she told reporters after posting bail.

"I'm saying and appealing to you not to be silent, even if and especially if you're next," she added.

• READ: Freed on bail, Maria Ressa rallies journalists to hold the line

The bail for Ressa's temporary freedom was set at P100,000, based on an order for her release seen by ABS-CBN News.

Maria Ressa’s release order. She was made to post bail at P100,000 | via @Nikobaua pic.twitter.com/7iscaZAif8

— ABS-CBN News (@ABSCBNNews) February 14, 2019

Ressa's camp will file a motion to quash the cyber libel case, said her lawyer JJ Disini.

• Cyber libel case vs Rappler riddled with 'deficiencies': Ressa lawyer

Ressa's arrest came after Duterte cracked down on high-profile critics in the press and legislature who opposed his signature anti-drug campaign that left thousands dead.

The cyber libel case against Ressa and former Rappler reporter Reynaldo Santos, Jr. meanwhile stemmed from a report about businessman Keng's alleged ties to the late ousted Chief Justice Renato Corona.

While investigators initially dismissed Keng's 2017 complaint about the article, the case was subsequently forwarded to prosecutors for their consideration.

• Ressa's libel accuser: 'No one is above the law'

PRESS ORGANIZATIONS SLAM ARREST

Journalists condemned Ressa's arrest, calling it an effort to silence critics.

"The arrest of ... Ressa on the clearly manipulated charge of cyber libel is a shameless act of persecution by a bully government," said the National Union of Journalists of the Philippines.

"The government ... now proves it will go to ridiculous lengths to forcibly silence critical media," it added.

Amnesty International also swiftly condemned the arrest as "brazenly politically motivated."

"In a country where justice takes years to obtain, we see the charges against her being railroaded," the group said in a statement.

A United Nations spokesperson told reporters in New York they were trying to get "a bit more detail" about Ressa's arrest but said Secretary-General Antonio Guterres "has always stood strong for freedom of the press and for governments to allow journalists to do their work in a way that is unharassed."

• Amanpour, Albright, international groups hit Maria Ressa arrest

The Philippines tumbled 6 places last year in Reporters Without Borders' press freedom index to 133rd out of 180, with the body noting that government has pressured and silenced critics.

Duterte has lashed out at other critical media outfits, including newspaper Philippine Daily Inquirer and ABS-CBN. He had threatened to go after their owners over alleged unpaid taxes or block the network's franchise renewal application.

Some of the drug crackdown's highest-profile detractors have wound up behind bars, including Senator Leila de Lima, who was jailed on drug charges she insists were fabricated to silence her.

Another administration critic, Maria Lourdes Sereno, was removed as chief justice in May last year based on a petition filed by Duterte's chief lawyer, Solicitor General Jose Calida.

Ressa has asserted that Rappler is not anti-Duterte, saying it is just doing its job to hold the government to account.

PALACE: RESSA CASE NOT TIED TO PRESS FREEDOM

The law that forms the foundation of the case against Ressa takes aim at various online offenses, including computer fraud and hacking.

Presidential spokesperson Salvador Panelo said the case has nothing to do with Ressa's work as a journalist.

"This has nothing to do with freedom of expression or the press," he told ABS-CBN News. "Regardless of who commits any crime, he or she will be charged in accordance with the law."

Rappler was also charged with tax evasion.

In the tax case, the government accused Rappler Holdings Corp., Ressa and the site's accountant of failing to pay taxes on 2015 bond sales that it alleged netted gains of P162.5 million.

Its incorporation certificate was also revoked last year for allegedly violating the constitutional restriction on foreign ownership of mass media.

- With a report from Agence France-Presse