A Chinese national was arrested in connection with illegally photographing Air Force planes at a military base in Nebraska, according to the Department of Justice.

The DOJ announced Thursday that the Chinese national, Tianrui Liang, allegedly was “illegally documenting” planes near Offutt Air Force Base in Nebraska, home to U.S. Strategic Command. Liang allegedly crossed the Canadian border March 28 on a valid B1/B2 visa and later drove to New York after being confronted by the FBI in Nebraska, according to the agency.

Liang also allegedly was at Ellsworth Air Force Base in South Dakota before visiting Nebraska and had plans to visit Tinker Air Force Base in Oklahoma, according to the Justice Department and The Associated Press. The FBI told the AP that it is illegal to sketch or photograph military installations without approval.

Offutt Air Force Base told a local news outlet in a statement that “to clarify, the individual in question did not gain access to Offutt Air Force Base.”

The Justice Department said Liang was arrested at John F. Kennedy International Airport on April 7, and he later appeared in federal court in the Eastern District of New York on a Nebraska federal charge. The judge released Liang, though federal prosecutors in Nebraska appealed the move, and he has been in the custody of the U.S. Marshals Service since April 10, according to the Justice Department.

Liang is set to be brought to the District of Nebraska for further proceedings, the agency said.

“Any individuals who unlawfully attempt to acquire sensitive information about military aircraft located in the District of Nebraska will be held maximally accountable under federal law,” U.S. Attorney Lesley Woods said in a statement.

The DOJ noted that “the criminal complaint is only a charge. Liang has not been convicted and is presumed innocent until proven guilty. If convicted, he is subject to a term of imprisonment of up to 1 year.”