A 5-year-old girl and a 5-year-old boy were found dead at an apartment building in the Bronx Monday morning, authorities said.

The two children were found inside an apartment on East 175th Street, between Monroe and Topping avenues in the Mount Hope section of the Bronx, around 11:20 a.m., police said. 

Emergency responders pronounced them dead at the scene, Assistant Chief Benjamin Gurley, the commanding officer of NYPD Patrol Borough Bronx, said at a press conference.

Neither of the children, who were twins, appeared to have trauma to their bodies, the NYPD said. Their names were not immediately released.

Police set up a crime scene inside the apartment, and an investigation is ongoing, Gurley said. 

"At this time, we do not know if there’s any foul play, being that the investigation is very fresh," Gurley said. 

The city's medical examiner and the NYPD's crime scene unit will process the scene and determine the cause of the children's deaths, Gurley added.

The FDNY told police that the air was safe inside the apartment, Gurley said.

There was no reported history of domestic violence at the home, nor were there any city Administration for Children’s Services cases connected to the family, Gurley added.

Gurley said the children’s mother was “there the whole time with them," but added that it wasn't clear if they were under constant supervision. The children's father was not home when the children were discovered, but police say he is cooperating with detectives.

The mother was taken to the hospital for treatment Monday, and while she is not injured, she is "emotionally distraught," Gurley said.

Dansoko Lansana told NY1 that he has lived in the apartment building where the children were found for over 25 years.

"I know the mother because I always see them in the hallway. Very responsible mother, very nice," Lansana said. "She always holds the kid in her hand. She doesn't let them make noise. Very respectful."

Gurley said that the twins were sent home from school with an illness last week, but it is unclear what that illness was and if it had to do with their deaths.

"It's really affecting me. I feel very, very sorry for them. I don't know what to say," Lansana said.