Three people have been arrested in connection with the mysterious deaths of 21 teenagers at a popular nightclub in South Africa, authorities said Wednesday.

According to a statement from the South African Police Service, the 52-year-old owner of the Enyobeni Tavern as well as two employees, aged 33 and 34, were taken into custody over the weekend and on Tuesday afternoon by a team of detectives investigating the incident in Scenery Park, a suburb on the edge of the coastal city of East London in South Africa's Eastern Cape province.

The names of the suspects were not released.

Police said the arrests were made after the Eastern Cape Liquor Board opened a criminal case against the Enyobeni Tavern for allegedly selling alcohol to minors.

Investigators subsequently issued fines of 2,000 South African rand (about $118) to the two employees and served a summons to the owner for his immediate arrest and appearance in a court of law, according to police.

The owner is scheduled to appear in East London Magistrate Court on August 19.

Each of the employees were given an option to pay the fine; but should they fail to do so, they will be required to appear in the same court on the same day, police said.

What caused the deaths of the 21 teens - 12 girls and nine boys - remains unknown. They were found at the Enyobeni Tavern in Scenery Park in the predawn hours of June 26. Seventeen of the victims were pronounced dead at the scene, while four others died when they were hospitalized or being transported to hospitals, according to police.

Police said the victims ranged in age from 13 to 17 - all under South Africa's legal drinking age of 18.

The local government, the Buffalo City Metropolitan Municipality, held a mass funeral for the victims in East London last week.

Thousands of people attended the symbolic service, including South African President Cyril Ramaphosa, who gave the eulogy for the young victims. The bodies were buried in private ceremonies at various cemeteries.

Toxicology reports were still pending as of Wednesday. A stampede has been ruled out because the bodies did not show any serious injuries, according to police.

Police have declined to comment on possible causes of deaths or the circumstances surrounding the incident, citing the ongoing investigation.

"Just as we said in the beginning, investigation is a process and needs to be treated with extreme care and wisdom so that we can achieve the desired outcomes which all of us will be proud of," the South African Police Service's commissioner for Eastern Cape province, Lt. Gen. Nomthetheleli Mene, said in a statement Wednesday. "This is the beginning of the great work we are doing behind the scene."

The Daily Dispatch, a South African newspaper published in East London, reported that the teens were attending a party at the Enyobeni Tavern to celebrate the end of June school exams. Their bodies were reportedly found strewn across tables, chairs and the dance floor with no visible signs of injuries.

A 22-year-old Scenery Park resident, Sibongile Mtsewu, told ABC News that he was at the Enyobeni Tavern when the deadly incident unfolded. He said he was ordering drinks at the crowded club when suddenly the doors were closed and some type of chemical agent, such as tear gas or pepper spray, was released into the air.

"There was no way out," Mtsewu told ABC News in a telephone interview earlier this month. "There was no chance to breathe."