BUENOS AIRES, Aug. 5 (Xinhuanet) -- Paraguayan president said Thursday that irregularities existed in the construction of the building, in which 504 people were killed in a weekend blaze on the outskirts of Asuncion, Paraguay's capital.

    "Bribery prevails," Nicanor Duarte said during his second visitto the site of the fire that destroyed Ycua Bolanos supermarket.

    Construction regulations were breached, and the buildings lack an efficient security system, the president said, adding there were not enough emergency exits and extinguishers.

    Bolanos said the incident, considered as the worst in the history of the country, must lead to reflections among people so as to avoid the repetition of the "terrible vices."

    The fire broke out when the supermarket was crowded with Sundaymidday shoppers. Reports said nearly 1,000 people had been inside the shopping center, which is part of the complex that also housesoffices and an underground parking lot.

    The supermarket owner Juan Pio Paiva and his son Victor Daniel Paiva, accused of manslaughter, were held in preventive detention on Tuesday, as eyewitnesses said the son ordered supermarket guards to close doors to prevent people from leaving without paying.

    Bolanos also applauded the work of the rescue personnel. He said 170 of them are hospitalized in Asuncion and 40 of them in intensive care.

    Forensic experts from Argentina, Colombia and the United Stateshave started investigations into the cause of the fire. Paraguay'sInterior Minister Orlando Fiorotto has ruled out a terrorist attack, saying that "investigations clearly pointed toward a gas leak and the rapid combustion of the merchandise." Enditem