MANILA (UPDATE) - The Commission on Human Rights (CHR) has initiated an investigation into the death of a 3-year-old who was caught in the crossfire during a police operation in Rizal on Sunday.

In a statement, CHR spokesperson Jacqueline Ann de Guia said the rights body has sent a team to investigate the death of Myka Ulpina in an anti-drug operation in Rodriguez town.

Her father, Renato Ulpina, and another companion was killed, along with undercover police officer Senior Master Sgt. Conrad Cabigao, in the incident.

Police said Renato had used his daughter as a shield amid gunshots, but the child's mother denied this, saying they were sleeping when the incident happened.

"As there are disputes in the claims of both sides on what transpired that unfaithful day, the Commission is monitoring the case and already dispatched a team to investigate. We ask the government to expedite the investigation on the matter and allow the rule of law to prevail," De Guia said.

She condemned how Ulpina's life "was cut short in the hands of those who swore to protect it." The child was supposed to turn 4 at the end of the month.

The Philippine National Police has relieved the entire roster of the Rodriguez police force in light of the incident.

Asserting the constitutional provision on due process, protection of life, liberty and property, and equal protection of the laws, De Guia said minors caught in the crossfire in the drug war "are simply not collateral damage," but victims.

"Their hopes and dreams fall short once bullet enter their bodies," she said.

While supporting the government's bid to end the drug scourge, the rights body said: "...[W]e continue to echo the sentiment that the end does not justify the means."

"As such, the success of the government's campaign to end illegal drugs should not merit on the number of drug suspects killed, but rather to the multitude of lives changed," she said.

Human rights group In Defense of Human Rights and Dignity Movement (iDEFEND), meanwhile, hit Philippine National Police (PNP) chief General Oscar Albayalde's statement that the death of police officers in drug operations prove how suspects had resisted arrest.

Albayalde cited the case of Cabigao, the officer slain in the same police operation where Ulpina was killed.

"iDEFEND laments the continuing loss of lives due to a bloody anti-drug war, and reiterates its challenge to the government to adopt a health-based, rights-based, evidence-based approach to the drugs issue," the group said.

It cited the lack of an "official and independent investigation" to determine whether victims of extrajudicial slays were "real drug criminals," if those slain in police operations indeed fought back, and if the reported police deaths were in legitimate police operations.

Earlier, Sen. Ronald dela Rosa defended the police operation where the child died, saying "s*** happens."

• 'Bato' on death of kid in police ops: S**t happens

Human rights lawyer Chel Diokno, meanwhile, scored Dela Rosa's seemingly dismissive comment as he sent sympathies to her family.

"No, Sen. Bato, this is not “shit happens.” This is what happens when government dispenses justice from the barrels of guns instead of the courts," he said in a statement.

He warned that as long as guns rule the drug war, more innocent children will die.

"Those responsible can never wash their guilt away. Their day of reckoning will come," Diokno said.

Latest PNP data showed that more than 6,000 drug suspects have been killed in police anti-drug operations from the start of the Duterte administration in July 2016 until the end of May this year.

• Over 6,000 killed in nearly 3 years of PH drug war: PNP

EDITOR'S NOTE: A previous version of this story mistakenly referred to the father as Renato Dolorfina.