The hostage situation at Hamburg Airport ended Sunday afternoon, around 18 hours after a man drove his vehicle through the gates of the airport with his 4-year-old daughter inside, authorities said. The man was arrested and the girl appears to be unharmed.

Hamburg police tweeted that “the hostage situation is over. The suspect has left the car with his daughter. ... The child appears to be unharmed.”

Police also said that “the man was arrested by the emergency services without resistance.”

The airport in the northern German city had been closed to passengers and flights cancelled since Saturday night when the man, who was armed, broke through an airport gate with his vehicle and fired twice into the air with a weapon, according to German news agency dpa. The man drove the vehicle just outside a terminal building and parked it under a plane.

Authorities said the man's wife had previously contacted them about a child abduction.

Police said that the 35-year-old man had his daughter inside the car after reportedly taking her by force from the mother in a possible custody battle.

A psychologist had been negotiating with the man for 18 hours. Nobody was injured during the standoff after all passengers had evacuated the airport, police said.

The mother of the girl also arrived at the airport earlier on Sunday.

Police spokeswoman Sandra Levgruen said that officers were checking whether the suspect “still has any explosive devices on him or with him or whether they are still in the car,” dpa reported.

"We are currently assuming that he is unharmed, but he is still lying on the ground in the care of the police,” she said.

More than 100 flights were cancelled and several planes were rerouted. Thousands of travellers have been affected by the standoff and hundreds were put up at hotels close by.

Police said Sunday afternoon that preparations were underway for the fastest possible resumption of flight operations.