NEW YORK (CBSNewYork) — The jail complex at Rikers Island was placed on lockdown Wednesday night after an inmate was reported missing.

New York City Department of Corrections spokesman Peter Thorne said an inmate apparently did not return from outdoor direction Wednesday evening.

Staff observed around 7:30 p.m. that the headcount was off by one, the DOC said.

“A thorough investigation is underway, which includes an active search for this individual in coordination with NYPD,” Thorne said in the statement. “Rikers Island facilities have been placed on lockdown and we are talking to anyone who may be involved.”

As CBS2’s Valerie Castro reported, vehicles were again coming onto and off the island by 11 p.m.

But during the lockdown, Q100 Metropolitan Transportation Authority bus service was suspended. Some riders said they were stranded since 7 p.m., waiting for people on the island.

“We were there since 7:15 on the bus – people passed out. You couldn’t get water; couldn’t get off the bus. They did not report any information for you at all and they – people were looking on their phones, and something popped up at 9 o’clock,” one woman said. “We were on the bus since 7:15.”

Other visitors told CBS2’s Valerie Castro the buses were searched and they were asked to show identification.

A source told CBS2 it was believed that the inmate may have jumped a fence.

NYPD Harbor Units were also on the scene because there was a report that the inmate was seen in the water, sources said. Police were searching the water in the area.

The DOC was not able to provide a description of the missing inmate late Wednesday.