A 52-year-old grandmother in Baltimore has been charged with first-degree murder for deliberately setting a New Year's Eve fire that killed two of her grandchildren, police said.

Latashia Hill, 5, and her sister Tonya, 4, were found in the third-floor back bedroom of their grandmother's brick row house, where the children's parents and others had celebrated the new year, according to police.

Police said the girls' mother, Alice Faith Conyers, was injured when she jumped from the third floor, while the father, Gary Hill, burned his hands trying to rescue the children.

Six others in the house were taken to area hospitals for treatment of injuries ranging from smoke inhalation to broken bones, police said.

Early yesterday, police charged Bertha M. Conyers with two counts of first-degree homicide.

Detective Mark Tomlin said the motive for the alleged crime remains unclear, but he said the suspect had been fighting with her boyfriend before the fire broke out.

Fire investigators said the blaze apparently was set with a flammable liquid that was poured on the second-floor stairs and along the second-floor hallway leading to the top floor, cutting off the children and their parents from the rest of the house.