The boyfriend of Miss Honduras 2014’s sister has confessed to killing her and the beauty queen after the two disappeared at a spa six days ago while they were celebrating his birthday, Honduran police announced Wednesday.

Authorities are awaiting confirmation from forensic officials that the bodies found buried in a river bank in mountainous Santa Barbara, about 240 miles west of Tegucigalpa, are Maria Jose Alvarado, 19, and her sister, Sofia, 23.

Plutarco Ruiz, boyfriend of Sofia, and an accomplice, Aris Maldonado, have been arrested, said Gen. Ramon Sabiillon, who is Honduras’ National Police director.

Sabillon said Ruiz confessed and led authorities to the bodies near La Aguagua spa, where they had gone Thursday to celebrate Ruiz's birthday.

Both women, who grew up in the area, were shot to death and appeared to have been killed the night they disappeared, Sabillon said.

"They were not very astute about assessing the people around them. They were just friendly," the sisters' mother Teresa Munoz told Televicentro. "They were taken out by people they hadn't known very long."

Ruiz and Maldonado said they buried the bodies near the river so they would decompose quickly, according to Sabillon.

"I can confirm that the Alvarado sisters were found ... We also have the murder weapon and the vehicle in which they were transported to the site where they were buried," Leandro Osorio, head of the criminal investigation unit, told local television, according to Reuters.

Sabillon said Ruiz allegedly shot his girlfriend, Sofia, because she was dancing with another man. After a fierce argument, he pulled out a pistol and fired at Sofia first, then Miss Honduras as she tried to flee.

Alvarado was crowned Miss Honduras in April and was expected to compete in the Miss World Pageant in London next month. She was supposed to have left for London this week. A pageant representative said Honduras would not compete in the contest this year, given the tragedy.

Alvarado’s Miss World profile page said she aspired to become a diplomat for Honduras and that she enjoyed playing sports and “performing the Punta Dance, a Garifuna music and dance style performed at celebrations and festivities.”

Teresa Munoz said Maria winning Miss Honduras was a dream come true for her.

“Ever since she was a little girl, she loved watching the beauty parades and I always sat down with my three daughters to watch competitions on television,” the mom told Honduran newspaper El Tiempo, according to the New York Post. “She (Maria) told me, 'One day, I will be Miss Honduras.’”

Honduras, overrun with streets gangs and drug-trafficking, has the highest murder rate in the world for a country not in war, with an estimated 90 to 95 killings per 100,000 people. It is one of Latin America's poorest countries and earlier this year was the main source of a surge in unaccompanied minors migrating to the United States, many to escape the violence.

The Associated Press contributed to this report.