Rio de Janeiro  - At least 15 people were killed and eight others were injured in a massacre presumably perpetrated by drug traffickers in the southern Brazilian town of Guaira on the border with Paraguay, Brazilian media reported Tuesday.

The killings were apparently a vendetta between rival gangs of smugglers of drugs and weapons, the police told Brazilian media.

The massacre in the state of Parana took place late Monday when an armed group of Brazilians arrived in town from the river that constitutes the border between Paraguay and Brazil, and then left for Paraguay by boat, according to Brazilian authorities.

A drug boss known as "Polaco" was apparently among the dead, along with two women and several boys.

Parana Public Safety secretary Luiz Fernando Delazari said late Monday that state authorities had formally requested the cooperation of Paraguayan authorities in order to find the killers.

He said at least five people took part in the massacre, according to a preliminary investigation, and most of the victims were involved in drug trafficking.

Eye witnesses and survivors told the authorities that the attackers arrived in the favela (slum) of Villa Santa Clara by boat, looking for "Polaco," who apparently owed drug traffickers in the region some 2,000 dollars.

"At one of the shacks, they found 'Polaco' and two women, who were murdered. Then they forced 'Polaco' to call his accomplices and ask them to meet near his home. As they arrived, they were caught by the killers, and they were all murdered," Delazari said.

The official noted that the injured only survived because the killers assumed they were dead.

Delazari said the attackers had all been identified, although he could not disclose their names, and were all Brazilian drug traffickers.

Guaira is on a new route for smugglers of cigarettes, drugs, weapons and electronic goods, the authorities said. (dpa)