LOUDOUN COUNTY, Va. (7News) — Four days after she disappeared early Thursday morning on a Dominican Republic beach, what happened to a missing college student from the Chantilly area remained a mystery Monday.

Although there were reports on Sunday that some law enforcement authorities in the Dominican think 20-year-old Sudiksha Konanki may have drowned, Loudoun County Sheriff Mike Chapman said Monday afternoon that nothing has been ruled out.

The Chief of the Civil Defense in the Dominican Republic told ABC News that they are expanding the perimeter of the area that they are searching.

As of Monday night, they are treating the disappearance as an accident, according to the Chief. The Cheif also confirmed that the man Konanki was with before she disappeared is not considered a suspect by authorities.

READ | Virginia college student reported missing during spring break in the Dominican Republic

Chapman said Konanki traveled to the Dominican Republic with a friend from Loudoun County and several other friends from the University of Pittsburgh, where a family friend said she was studying medicine.

Chapman said when she disappeared early Thursday morning, she was with one of the friends she traveled with as well as several other people who were not part of her group.

“They were not people that traveled with her. They were not people from the University of Pittsburgh. They were people that they met down there, and that’s all I can tell you at this point,” Chapman said Monday afternoon.

“It’s an ongoing investigation, so there are things that I know that I can’t tell you, but what I can tell you is that that person is being interviewed,” Chapman said, adding that the others who were there that morning have also been interviewed.

Chapman said friends who had traveled with Konanki had been expected to travel back to the U.S. on Monday, but they are remaining in the Dominican Republic for now.

From the Dominican Republic, Konanki’s father, Subbarayudu Konanki, said he had last spoken with his daughter the night before she disappeared.

“[She was on] spring break, and everything was going okay. And she was really happy,” he said in an interview shared by ABC.

Prior to becoming a student at the University of Pittsburgh, Konanki graduated from the prestigious Thomas Jefferson High School for Science and Technology in Fairfax County, which students from Loudoun County can apply to go.

“She’s a brilliant student. And calm, easygoing, not a party girl or anything,” said Shekar Pendem, a close friend of the Konanki family who lives next door to them in Chantilly. He said he had known Konanki since she was a toddler.

Although the Defensa Civil Dominicana said on its Facebook page that helicopters, drones, and K-9 dogs have been used in the search for Konanki, Pendem says he feels the area being searched needs to be widened beyond the beach area where Konanki disappeared. When she vanished, she was visiting the RIU Hotel & Resort in Punta Cana.

“We need to put more pressure on the local government so that they expand the search beyond the perimeter,” Pendem told 7News. “It’s so sad. Me and family and everybody, we are really hoping some miracle happens, and we see her back. We are just really praying and hoping for her return.”

Sheriff Chapman said he has been in contact with U.S. federal authorities who are on the ground in the Dominican Republic. Those who are there include the FBI, which is assisting Dominican authorities.

“She’s a Loudoun County resident. That means a lot to us,” he said. “And we feel so bad for the family. We want to make sure that we’re doing everything that we can to help the family out.”

Chapman said the Loudoun County Sheriff’s Office was contacted early Thursday evening about Konanki’s disappearance, and he said Dominican authorities had been contacted earlier in the day.

On Monday, RIU Hotels released a statement about Konanki’s disappearance.

“From the moment her absence was reported, we have been working closely with the local authorities, including the police and the navy, to conduct a thorough search,” a portion of the statement read. “We would like to express our deepest sympathy to the family and friends during this incredibly difficult time.”

The statement also said RIU Hotels has set up an internal communication channel so employees can share any relevant information on the disappearance. Chapman asked that anyone in Northern Virginia with relevant information contact the Loudoun County Sheriff’s Office.

If you have any information on the whereabouts of Konanki, contact LCSO at 703-777-1021.