MANILA (UPDATE) - Senator Leila de Lima on Saturday marked her first year in detention, unwavering in her resolve to never be silenced.

Family, friends and colleagues from the Senate visited De Lima at the Philippine National Police Custodial Center in Camp Crame, Quezon City as she marked a year since her arrest.

A mass is set to be held at her detention room Saturday afternoon celebrated by Lingayen-Dagupan Archbishop Socrates Villegas.

De Lima, among the administration's most vocal critics, has been detained on drug charges she has decried as political persecution. Throughout her detention, she has continued to speak out about state affairs through issuing handwritten dispatches.

Among personalities seen arriving at the custodial center were De Lima's fellow opposition lawmakers Sen. Bam Aquino and Senate Minority Leader Franklin Drilon, former senator and Interior Secretary Mar Roxas, and former Solicitor General Florin Hilbay.

Senator Bam Aquino arrives at the PNP Custodial Center to visit Senator Leila de Lima. A holy mass is expected to be celebrated inside. pic.twitter.com/fPTXMoq6lY

— Kevin Manalo (@Kev_Manalo) February 24, 2018

LOOK: Former SolGen Atty. Florin Hilbay awaits the permit to visit Sen. De Lima inside the Custodial Center. pic.twitter.com/nJ6XHUxzWh

— Kevin Manalo (@Kev_Manalo) February 24, 2018

Senator Franklin Drilon follows right after Hilbay. Other opposition members expected to join the mass as well. pic.twitter.com/RtNdE7adtu

— Kevin Manalo (@Kev_Manalo) February 24, 2018

Mar Roxas would not miss the mass for Sen. De Lima. pic.twitter.com/2TvffUThCX

— Kevin Manalo (@Kev_Manalo) February 24, 2018

As the media awaited the arrival of other guests outside the custodial center, police barred them from further coverage, saying the area was restricted.

Supporters of the feisty senator meanwhile held a protest outside Camp Crame around 10 a.m. to again call for her release.

"Hindi po nalilimutan ng bayan si Senadora De Lima at 'yung injustice na nangyari sa kaniya. Lalaban po kami para sa kaniya," said Regina Mabalatan, a supporter of the senator.

(The nation has not forgotten Sen. De Lima and the injustice done to her. We will fight for her.)

Supporters say they are inspired of de Lima being an articulate critic of the government. pic.twitter.com/I0D3jbmZnd

— Kevin Manalo (@Kev_Manalo) February 24, 2018

A former Justice Secretary and Commission on Human Rights Chair, De Lima was arrested on Feb. 24, 2017 due to her alleged involvement in the illegal drug trade inside the national penitentiary.

She has denied the allegations, saying her incarceration was meant to silence her.

• De Lima detained, determined to clear name
• Detained De Lima hopeful 'justice will come'

While detained, De Lima has earned the support of several rights watchdogs who believe that her detention was meant to stifle dissent.

And even behind bars, the senator continued to gain recognition from several human rights bodies.

Last year, the senator received the “Prize for Freedom” Award by Liberal International and was included in Foreign Policy’s “50 Leading Global Thinkers of 2017.”

• De Lima gets top human rights award from int'l group

De Lima was also part of TIME Magazine's list of 100 most influential people in the world for 2017 alongside President Rodrigo Duterte.

The list placed Duterte under the "Leaders" category, while De Lima was listed among "Icons."

• Adversaries Duterte, De Lima on TIME list of most influential people

'MOTHER OF ALL DRUG LORDS'

Malacañang, meanwhile, hailed De Lima's detention, saying it is proof that the criminal justice system in the Philippines is "alive, effective, and working."

In a statement, Presidential Spokesperson Harry Roque greeted De Lima a "happy anniversary."

"Let me first greet Senator Leila de Lima a happy anniversary. Senator De Lima’s incarceration shows that the criminal justice system in the Philippines is alive, effective and working," he said.

Roque also called De Lima the "mother of all drug lords" for allegedly allowing the illegal drug trade to proliferate inside the national penitentiary during her time as justice chief.

"Senator De Lima’s case is now pending in our courts. Let us therefore refrain from influencing the outcome of her case and just let the legal process proceed accordingly," he said.

De Lima had previously said her faith has never wavered and that she believes justice would come.

"Maipakulong man nila ako, hindi ko kailanman isusuko ang aking mga ipinaglalaban. I will never be silenced. Paulit-ulit ko pong sinasabi ito," said De Lima.

(They may have me jailed, but I will never give up what I am fighting for. I will never be silenced. I say this again and again.)

• De Lima to launch e-book featuring letters from detention