Isa sa mga lalaking nawalan ng malay matapos dumalo sa concert sa Pasay kagabi, pumanaw na rin.

— Raphael Bosano (@raphbosano) May 22, 2016

MANILA -- Five people died Sunday after attending a concert at the parking lot of a mall in Pasay City on Saturday night.

The fatalities were identified as Ariel Leal, Lance Garcia, Bianca Fontejon, and a male American national.

The fifth victim, Ken Migawa, who was earlier reported to be in critical condition, has also died Sunday night.

The victims were found unconscious at different parts of the concert venue at the SM Mall of Asia.

Investigating officer Giovanni Arcinue, in an interview with Agence France-Presse, said police were looking at possible heatstroke or dehydration as the country is sweltering under high temperatures brought on by the El Nino weather phenomenon.

He also said it was too early to say that the deaths were caused by drug-laced drinks, despite rumors spreading on social media.

Close-up and its media partner, Eventscape, said in a joint statement that stringent measures and precautions were put in place to ensure the safety of all concert attendees.

A photo posted by Closeup Philippines (@closeupph) on May 22, 2016 at 4:17am PDT

They added that strict protocols were followed in providing immediate medical assistance to the victims and in rushing them to the nearest hospital.

They also committed their support to the families of the victims while ensuring full cooperation with the police investigations.

SM Supermalls, likewise, expressed its sympathies. Company president Annie Garcia said SM is assisting the event organizers and authorities in their investigation. -- With reports from Raphael Bosano, ABS-CBN News; Raya Capulong, dzMM; Agence France-Presse