Boston police investigating the murder of a young brother and sister said they have no suspects in the case and that "all signs kind of point to the mother."

The children's cause of death is still being determined.

Yasmin Burgos, 12, and Dennis Burgos, Jr., 10, were originally thought to have been stabbed to death in what police are calling a domestic incident, but authorities said Tuesday that the cause of death was not clear. Autopsies were being performed on the children Tuesday.

The children's mother, 31-year-old Angela Vasquez, was hospitalized for stab wounds that are suspected of being self-inflicted. She has reportedly undergone surgery.

A spokesperson for the Boston Police Department said Tuesday that no other suspects are currently being pursued in the killings.

"There was no one else in the house at the time of the incident and we can't yet implicate the mother in the crime, even though it clearly seems that way," a police spokesperson said.

The family was on the radar of local child welfare authorities. The Department of Social Services in 1998 had launched an investigation of the mother for child neglect but considered the problems to be resolved when the case was closed in 2000, spokesman Michael McCormack said.

According to the Boston Globe, police discovered the bodies after being sent by a social worker to check on the family.

Friends of Vasquez told reporters Monday that her life had taken a bad turn in the weeks leading up to Sunday's killings. Her father had passed away, she had recently been left by her boyfriend and she lost her job at Boston Children's Hospital.

Vasquez also sent text messages to her friends saying that she was leaving town.

"She was a hard worker and a very good mother," Vasquez's younger sister, Christina Lopez, told MyFoxBoston.

Investigators intended to talk to Vasquez after she got out of surgery.

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The Associated Press contributed to this report.