LINCOLN, Neb. (AP) — Nebraska prison officials are keeping an eye on new technology being used to smuggle contraband into state prisons, including drones.

A crashed drone attached with bags of marijuana and tobacco was found at the Lincoln Correctional Center two months ago. The Justice Department reported last year an increasing number of attempts to use drones to smuggle contraband into federal prisons over the past five years.

The state prisons’ Centralized Intelligence Unit formed last year identifies and stays ahead of technology trends, said Christopher Connelly, agency intelligence administrator at the Nebraska Department of Correctional Services.

“Really, there’s so many ways that contraband can come in, whether it comes in through the front entrance or a laundry cart or delivery truck,” said prisons spokeswoman Dawn-Renee Smith.

“Or dropped in by a drone,” Connelly said.

Prisons are refocusing efforts to locate and recover contraband, particularly cellphones, which has become a growing issue, said Smith. Inmates can use cellphones to track prison staff’s home addresses or transact business, Connelly said.

More than 165 cellphones were seized last year in the state’s 10 prison facilities, according to a Corrections Department report. Nearly 65 were found in 2016 and almost 80 in 2015.

Prisons are using new detection technology, Cellsense, to find cellphones that have been smuggled inside, said Smith. Trained dogs are also used.

While prisons have seen a spike in cellphones found within prison walls, drugs and alcohol still top the list of contraband found in Nebraska’s prisons.

In nearly 5 percent of cases in 2016, amphetamines, alcohol, cocaine and marijuana were detected in inmates’ systems across the penal system, according to the latest available department data.

Connelly said the growing number of ways that inmates can smuggle in contraband means that staff must be hyper-vigilant.