BRADENTON, Fla. (WFLA) — A Florida mother was arrested after shoving a pregnant school bus assistant because the bus was 30 minutes late, police said.

The assistant, who is nine months pregnant, said the bus was dropping off children on Oct. 2 when a child’s mother entered the bus, screaming and cursing, and pushed her into a wall. She told officers the mother, Erica Piedra, 36, was irate because the bus was 30 minutes late.

The assistant reported the incident four days later.

Detectives called the bus driver, who confirmed the assistant’s story. When questioned by police, Piedra said she only cursed at the victim but did not get onto the bus or shove the assistant.

Piedra was arrested and booked into the Manatee County Jail on Tuesday on a charge of aggravated battery on a pregnant woman.

There were no injuries, and the camera footage does not have the angle of the bus stairs where the incident took place.