On the evening of Monday, August 18, the US Army commenced unannounced military exercises in Minneapolis and St. Paul, Minnesota. MH-60 variant Black Hawk helicopters buzzed through the downtown and residential areas of the two Midwestern cities.

The ominous exercises, which took place over three days, were led by the Department of Defense and the Department of Homeland Security in close collaboration with the local police. They were carried out without public warning, despite the fact that they included late-night low flyovers of residential districts by thunderous war equipment.

Hundreds of stunned residents placed emergency phone calls in the hours after exercises began as several black helicopters weaved in between skyscrapers of both cities and swept through areas at low altitudes and high speeds. It was only after the widespread response that the police and military acknowledged what was taking place. (Video of part of the exercises can be found here.)

“We understand the concern and confusion these activities may have created for the public,” said St. Paul Police Department spokesman Howie Padilla as he defended the exercises.

St. Paul Police Federation Dave Titus responded to these safety concerns by proclaiming, “Controlled practices like these ultimately save lives and make a safer environment for everyone.” The helicopters that flew over the two Minnesota cities are designated for stealth operations ranging from support and reconnaissance to attack missions in various settings. They are generally armed with machine guns and can fly at speeds of up to 300 km/h.

The helicopters were piloted by teams from the Army’s 160th Special Operations Aviation Regiment, whose combat nickname is the “Night Stalkers.” The regiment, based out of Fort Campbell, Kentucky, has participated in a wide range of imperialist interventions, ranging from Mogadishu, Somalia to the war in Iraq.

Major Allen Hill, speaking for the regiment, claimed that the exercises were for “training” purposes. He attempted to downplay the significance of the exercises, noting that they take place “ten to 15 times a year throughout the country.” Hill said cities like Minneapolis and St. Paul “[provide] our pilots an unfamiliar environment—an area [the soldiers] are not accustomed to. Towns like Minneapolis, St. Paul, Dallas, Phoenix, Houston, they’re all great hosts. The cities invite us.”

Tonya Tennessen, spokesperson for St. Paul’s Democratic Party Mayor Chris Coleman, confirmed that Coleman and Minneapolis Mayor Betsy Hodges (also a Democrat) did invite the military to perform combat training over residential neighborhoods and refrained from notifying the public about the exercises.

“In a post-9/11 world, this is how homeland security happens,” Tennessen said. “These exercises are taking place in cities all over the country.”

Indeed, similar incidents have been reported in the previous two years around the US as part of “urban operations training” exercises. Minneapolis and St. Paul hosted similar military helicopter exercises in 2012, though on that occasion police notified the public of the exercises three days before they began.

The increasing regularity of urban warfare training involving military forces in the United States should be seen as a sharp warning to the working class. They are part of a number of steps directed at preparing for the use of these forces in operations within the country—directed at social and political opposition.

In April 2013, police placed the city of Boston, Massachusetts under de facto martial law after the city’s marathon race was bombed by Dzhokhar and Tamerlan Tsarnaev.

This month, the population of Ferguson, Missouri has also been placed under effective police rule. Peaceful protesters who sought to express their frustration with the police murder of an unarmed youth were met with tear gas and rubber bullets from police officers armed with combat equipment. Journalists reporting on the events in Ferguson faced similar treatment.

Police forces throughout the country are not only equipped with military gear, they have direct relationships with the military—as the Minneapolis warfare exercises make clear.

These preparations line up with the military plans put forward in the recently-released US Army Strategic Studies Group paper titled “Megacities and the United States Army: Preparing for a complex and uncertain future.”

The document makes the case for urban warfare against domestic opposition: “Failing to prepare for military operations in dangerous megacities could leave a future president without the means to do something that he or she considers to be in the national interest,” it reads. Among the cities cited in exercises for urban combat is New York City.

The training exercises in Minneapolis and St. Paul are not isolated events—they are part and parcel of preparations by the American ruling class for imperialist war abroad and for an intensified attack on the democratic rights of the population domestically.