CHICAGO - Three young men were arrested in south Chicago just days ahead of a NATO summit for suspected attempts to attack President Barack Obama's campaign headquarters, Mayor Rahm Emanuel's house and police stations with "incendiary devices," local media reported Saturday.

The men, who are held on $1.5 million bond apiece, are charged with conspiracy to commit terrorism, providing material support for terrorism and possession of an explosive or incendiary device.

The three men are self-proclaimed anarchists and members of "Black Bloc," a band of protesters who typically mask their faces to avoid identification.

Their arrests were the result of an investigation since early May into a group suspected of making Molotov cocktails - crude bombs usually created by filling glass beer bottles with gasoline, according to local court records.

The men traveled from Florida to the Chicago area ahead of this weekend's NATO meetings in order to prepare a multi-staged attack against various targets in the city, prosecutors said.

According to court documents, the men planned to first attack four Chicago police stations and destroy several squad cars with "destructive devices" in order to divert attention.

The group intended to attack Obama's national campaign headquarters in the Prudential Building, Emanuel's home in Ravenswood and other downtown financial institutions, prosecutors said.

The group had already done reconnaissance work on the Chicago Police Department headquarters in Bronzeville in preparation for the attacks, law enforcement officials said.

Local court documents suggest the three men had been in Chicago since at least early May and were living in an apartment in Bridgeport, a working-class neighborhood on the city's South Side.

When police raided the apartment Wednesday evening, they recovered four completed Molotov cocktails and weapons including a mortar gun, swords, a hunting bow, throwing stars and knives, according to law enforcement records.

They also possessed protective gear such as pre-positioned shields, assault vests and gas masks to help hide their identity during the planned attacks, prosecutors said.

In the recorded conversations, the men discussed attacking other judicial targets, planned escape routes and held late-night training sessions for engaging in combat with police, prosecutors said.