ROCKLAND — A 19-year-old Northport father has been charged with assaulting his infant daughter by breaking her ribs and sticking his finger down her throat in an effort to stop her from crying.

Neil Lagasse was held Thursday at the Two Bridges Regional Jail in Wiscasset after a Knox County Superior Court judge set bail at $1,000 cash.

Emergency room staff alerted police on Dec. 23 to an 11-week-old girl being treated for serious injuries, including broken bones, according to an affidavit filed by the Waldo County Sheriff’s Office.

The affidavit said the infant’s airway had collapsed and she was having difficulty breathing. Waldo County General Hospital staffers in Belfast were able to open the airway but had her flown to a Portland hospital in a LifeFlight helicopter as a precaution. The infant also had suffered three broken ribs, according to the affidavit.

Lagasse admitted to police that he had stuck his finger down the child’s throat because she would not stop crying, according to the affidavit. He brought her to the hospital when she was having trouble breathing.

Police also reported that he admitted grabbing her aggressively under her arms and pulling her from an infant swing because she would not stop crying and that this could have caused the broken ribs. That occurred a few days before he took her to the hospital.

According to the Waldo County Sheriff’s Office, the baby was out of the hospital Thursday morning and her condition is improving.

Justice William Stokes set bail during an initial video appearance by Lagasse.

Lagasse is charged with Class B aggravated assault and Class C domestic violence assault, both felonies. He did not enter a plea Wednesday and is scheduled to appear in court again Feb. 14.

Before he can be released on bail, he must enter into a supervision contract with Maine Pre-Trial Services. If he makes bail, he will be prohibited from having contact with his 11-week-old daughter or with any children younger than 6.