The children's father left the house after trying to rescue his family, CNN affiliate WJTV reported. He was taken to a hospital with injuries, the station said.
"When he is able to talk to our investigators, we can find him," said Jones. "We know that he was worried and worried and being treated by our paramedics and … at that moment he didn't want to leave the scene."
The house was built in 1951, said Jones. Investigators will look at why the mother and her children were unable to escape.
"One of the things we are going to see, what could have prevented or made the family unable to leave," he told reporters. "It would be anti-theft bars. We will look for smoke alarms and other smoke detection devices, as well as communications to make the 911 emergency call."
Deputy head of state, fire marshal Ricky Davis, in a statement, urged residents to take safety precautions to prevent fires.
"PLEASE, PLEASE, PLEASE, PLEASE, make sure you smoke alarms in your home before you sleep tonight," the statement said, WJTV said. "If your smoke alarms don't work or you need smoke alarms, contact your local fire department and they will install some for free."
"We are heartbroken to confirm that seven people were lost in this fire," said the city on Facebook.
"Although we do not know the cause of the fire," the newspaper said, "we do not suspect a dirty move. It was a tragic day for our city. We ask for your prayers for this family and our first responders. Ask this community to get involved in prayers and kindness while we all mourn together ".
Firefighters responded shortly after midnight, said John Alman, deputy head of the Clinton Fire Department.
The cause of the fire was under investigation, Alman said.
The names of the victims were not immediately released. They range from 1 year to 33 years, reported WJTV.