The leads came from the Transportation Security Administration, which supplied ICE with records on more than 31,000 travellers for possible immigration enforcement, the data showed.
Reuters could not determine how many arrests took place inside airports, although the TSA tips would mainly be useful in determining when a person would ​be travelling.

ICE and TSA are part of the US Department of Homeland Security.

The agencies have historically shared information related to national security ​threats, but they began focusing on routine immigration arrests last year as part of Trump’s mass deportation effort.

THE TSA PROGRAM ⁠WAS DESIGNED TO COUNTER TERRORISM

The 31,000 traveller records were gathered by TSA’s Secure Flight Program, which was created in 2007 to allow the agency to ​review passenger information for people who may be on US government watchlists.

The program was intended as a counter-terrorism measure, not to track down immigration offenders, ​according to the regulation outlining its purpose.

DHS did not respond to questions about TSA providing passenger information to ICE, but said that under Trump, TSA “is pursuing solutions that improve resiliency, security, and efficiency across our entire system.”

Figures for arrests and traveller records that TSA shared with ICE before Trump’s current term were unavailable.

US airports and immigration enforcement have been ​at the centre of a partisan funding fight since mid-February, when Democrats refused to support additional money for the Republican president’s immigration crackdown without reforms to ​scale back aggressive tactics.

The standoff blocked the passage of a bill to fund DHS, which caused TSA security officers to miss at least two full paychecks.

After some unpaid ‌TSA officers ⁠began calling in sick, Trump deployed ICE officers to more than a dozen airports in March to aid security efforts.

Democrats have criticised the deployment and called on the Trump administration to remove them.

A group of more than 40 Democrats in the US House of Representatives wrote in a letter to recently installed Homeland Security Secretary Markwayne Mullin last week that ICE officers “will cause confusion and fear“ if allowed to remain in airports.

REPORTS OF UNEXPECTED AIRPORT ARRESTS

Several cases ​of ICE officers arresting travellers in US ​airports have sparked backlash.

ICE officers detained ⁠a college student travelling from Boston to Texas to celebrate Thanksgiving in November and arrested a sobbing mother at San Francisco International Airport the day before Trump’s airport deployment began.

DHS defended both arrests and said they were subject to final ​orders of removal.

Reuters spoke with three immigration attorneys who said they were familiar with cases of people without ​legal immigration status ⁠being arrested in airports.

The cases included an Irish couple who had lived in the US for more than two decades and were detained last summer by immigration authorities in front of their children when trying to fly from Florida to New York after a vacation, Christina Canty, one of the lawyers, said.

The parents - who ⁠had pending ​applications for permanent residency - were deported and left their two young children, ages 7 and 10, with ​adult siblings in the US, Canty said.

In another case, a Chinese woman with a final order of removal who was seeking permanent residence was detained by ICE last year at the ​Atlanta airport en route to Philadelphia, one of the attorneys said.