A Boeing jet sat on the tarmac at Salt Lake City International Airport’s general aviation area Monday as dozens of people, most of them in handcuffs and ankle restraints, were directed to walk up a staircase to board it.

A photographer for The Salt Lake Tribune saw workers in plainclothes, not labeled with the name of any agency, removing people from four white vans with U.S. government license plates. One of the women who later boarded the plane was seen wearing pajama pants and slippers.

Less than two hours after it landed in Salt Lake City, the plane took off. It went to California, then to a location in Texas that’s home to a large U.S. Immigration and Customs Enforcement detention facility.

Spokespeople for ICE did not respond to a request from The Tribune to confirm whether the Eastern Air Express charter was one of the agency’s flights.

A spokesperson for the airport said Monday that she could not confirm whether ICE had chartered the flight because the east side of the airport, where the agency was loading passengers, is controlled by two companies who lease the area from the city’s Department of Airports. The two companies handle general aviation, according to the airport’s website, separate from the commercial aviation familiar to travelers. The Utah Air National Guard, as well as government, military and corporate aviation, are hosted on the airport’s east side.

What is known about the plane, including the company that operates it, suggests it’s being used by ICE.

According to ADS-B Exchange, a website that tracks air traffic across the country, the plane took off Sunday night from Newark Liberty International Airport. It arrived at Mesa Gateway Airport, near Phoenix, shortly after midnight local time, and took off at 7:42 a.m.

The plane landed at Salt Lake City International Airport just after 10 a.m., according to the exchange, and took off almost two hours later, headed for Southern California Logistics Airport in Victorville, Calif. — a former U.S. Air Force base about 65 miles northeast of Los Angeles.

It landed there at 1 p.m., took off just before 3 p.m. and landed at 4:14 p.m. in El Paso, Texas. El Paso, at the far southwestern tip of Texas, is home to two ICE detention facilities, according to the agency’s website.

ICE officials told the Washington Post earlier this month that the agency was keeping one of those facilities, Camp East Montana, open after terminating a $1.2 billion contract with a company that had overseen the camp’s construction and operation. ICE awarded a new contract to a different company, the Post reported.

On March 19, the same plane had flown from Salt Lake City to Harlingen, Texas — on the Lone Star State’s far southern tip. ICE’s Harlingen field office oversees seven detention centers in the Lower Rio Grande Valley, according to the agency’s website.

The plane is a Boeing 737-800, with a capacity of up to 189 passengers. The plane is operated by Eastern Air Express, a charter airline based in Kansas City, Missouri.

In the last year, Eastern has received $43.5 million in a contract with the Department of Defense, according to a contract database. The contract is with the defense department’s U.S. Transportation Command.

In January, Massachusetts Gov. Maura Healey demanded that Eastern and another private airline stop providing flights to transport people detained by ICE, the Worcester Telegram & Gazette reported. WFYI, the public radio station in Indianapolis, reported in October that Eastern was running flights for ICE in Indiana.