MANILA >> A Philippine opposition senator and leading critic of President Rodrigo Duterte’s deadly anti-drug crackdown was arrested today on drug charges but professed her innocence and vowed she would not be intimidated by a leader she called a “serial killer.”

Sen. Leila de Lima’s arrest came a day after the Regional Trial Court in Muntinlupa city in the Manila metropolis issued the warrant for her arrest along with other officials who have been charged by state prosecutors for allegedly receiving bribes from detained drug lords.

De Lima has denied the charges, which she said were part of an attempt by Duterte to muzzle critics of his crackdown, which has left more than 7,000 drug suspects dead. She questioned why the court suddenly issued the arrest order when it was scheduled today to hear her petition to void the three non-bailable charges.

“If they think they can silence me, if they think I will no longer fight for my advocacies, specially on the truth on the daily killings and other intimidations of this Duterte regime, it’s my honor to be jailed for what I’ve been fighting for,” she said before policemen took her into custody at the Senate.

A police convoy, trailed by media vans, took de Lima to the main police camp, where officers will take her photograph and fingerprints before her detention.

Presidential spokesman Ernesto Abella called de Lima’s arrest “a major step forward in the administration’s anti-drug war.”

When de Lima headed the government’s Commission on Human Rights, she tried unsuccessfully to have Duterte prosecuted when he was mayor of Davao city for allegedly unlawful deaths that occurred during an anti-drug crackdown in the city. No witnesses came forward then to testify against the mayor, human rights officials said.

Duterte expanded the crackdown nationwide after becoming president last June, and de Lima has continued to criticize him after winning a Senate seat last year.

In one of her strongest statements against the president this week, de Lima called Duterte a “sociopathic serial killer” who has not been made to answer for more than 1,000 deaths during his crackdown in Davao city as its mayor and now for the thousands of drug suspects killed in his national fight against illegal drugs.

She urged Duterte’s Cabinet members to declare him unfit to serve as president. Justice Secretary Vitaliano Aguirre II warned that such remarks were seditious, but de Lima replied that Aguirre and Duterte are “the rebels and inciters against a constitutional order that values life and due process above everything else.”

Prosecutors allege that de Lima, while she was justice secretary under former President Benigno Aquino III, received bribes from detained drug lords to finance her senatorial campaign, and they say some of the drug lords would testify against her. The bribes were allegedly solicited by her former driver and lover, who was also charged and arrested Thursday in northern Pangasinan province.

Duterte has lashed out at de Lima with foul language, calling her a sex-crazed immoral woman whose election opened “the portals of the national government … to narco politics.”

De Lima said the case against her might be the “wakeup call” the country needs, referring to the absence of a public outcry in the country over the killings in the anti-drug campaign.

De Lima said people were starting to fight back, citing recent accounts by a former militiaman and a retired police officer who acknowledged their roles as assassins in the Davao deaths and Duterte’s alleged involvement in the killings.