The number of children who died as a result of a fire in their Minnesota home has risen to three, family members said Saturday.

At a news conference, Pa Cheng Vang, the children's father, said he was grateful for the community's support since the fire broke out early Wednesday. He was at work at the time.

The children were identified as 5-year-old twin girls Sivntxhi Vang and Ntshiab Si Vang, and a 4-year-old boy, Manj Those Nutj Vang. Sivntxhi died Wednesday. The family announced the two other deaths Saturday,

A 1-year-old and their 28-year-old mother remained hospitalized in critical condition, they said. Two other children also remain hospitalized, but their conditions have improved.

"I highly encourage every single family to start practicing fire drills at home, especially in the middle of the night," the father told reporters. "I don't want any family, or the community, to see faces (in the) same condition as my family."

St. Paul Mayor Melvin Carter joined the family at the news conference, saying he knew the couple and their children because Vang's wife, Ker Lor, had previously interned in his office.

"You've endured all of our worst nightmares," the mayor said.

The cause of the fire was accidental, but it remains under investigation, Deputy Fire Chief Roy Mokosso said earlier. The home had working smoke detectors.