Democrats have called for a ban on immigration agents wearing masks and are pushing for increased oversight of their operations.

The United States Department of Homeland Security (DHS) ran out of funding over the weekend, leading to the third partial government shutdown of President Donald Trump’s second term, as negotiations between Republicans and Democrats remain stalled while Congress is in recess until February 23.

Democrats are calling for changes to the DHS’s immigration operations after two fatal shootings of US citizens in the city of Minneapolis last month. Alex Pretti and Renee Good were shot dead by federal officers from Immigration and Customs Enforcement (ICE) and Border Patrol during such operations.

On Monday, state officials in Minnesota said that the FBI has refused to share evidence with state law enforcement following Pretti’s killing on January 24.

“This lack of cooperation is concerning and unprecedented,” Minnesota’s Bureau of Criminal Apprehension superintendent, Drew Evans, said in a statement.

DHS entered a shutdown on Saturday, but will continue operations deemed essential. Cuts affect agencies under the DHS, including the Transportation Security Administration (TSA), the Federal Emergency Management Agency (FEMA), Customs and Border Protection (CBP) – which runs Border Patrol – ICE, and the US coastguard.

At US airports, 2,933 of the TSA’s 64,130 employees have been furloughed for the duration of the shutdown. The remaining 95 percent of staff will remain on duty but will work without pay until the DHS is funded.

Earlier this month, Democrats sent Republicans a list of 10 demands to rein in immigration enforcement. In a letter, authored by House of Representatives Minority Leader Hakeem Jeffries, the politicians called for increased oversight of the DHS.

The letter called for DHS officers not to enter private property without a judicial warrant and to require verification that someone is not a US citizen before placing them in immigration detention. It also called for DHS to mandate that its officers do not wear masks, have visible identification, and wear clear uniforms.

Democrats are also seeking to prohibit immigration enforcement actions near courts, medical facilities, houses of worship, schools, and polling places.

They further called for increased coordination with local and state agencies after the federal government blocked state and local law enforcement from participating in investigations related to the deaths in Minneapolis.

“Federal immigration agents cannot continue to cause chaos in our cities while using taxpayer money that should be used to make life more affordable for working families,” Jeffries said in the letter.

“The American people rightfully expect their elected representatives to take action to rein in ICE and ensure no more lives are lost. It is critical that we come together to impose common sense reforms and accountability measures that the American people are demanding.”

Tom Homan, Trump’s border chief, dismissed the calls from Democrats on CBS’s Face the Nation, referring to the requests as “unreasonable”.

Republican Senator Markwayne Mullin of Oklahoma, meanwhile, echoed Homan’s stance. On CNN’s current affairs programme, State of the Union, he claimed that Democrats are engaging in “political theatre”.