Ernst-Volker Staub, 61, Burhard Garweg, 47 and 57-year-old Daniela Klette are former members of the Red Army Faction (RAF), which sowed terror in the 1970s and 1980s with bombings, kidnappings and killings.
The three are now wanted for a spate of robberies on money transporters and at least six supermarket cash heists.
Police "have reason to believe that the three are living in the Netherlands," a statement said.
"Crimes were committed on the Dutch-German border, they have not yet been detained in Germany and a mobile phone belonging to one of the fugitives was switched off in The Netherlands," it added.
Between €46,000 and €100,000 were stolen in each hold-up -- except on May 7th, when the robbers escaped with a guard's firearm but no cash, and on June 6th.
On that day another cash-in-transit van was attacked and shot up with an AK-47 assault rifle. The attackers fled without taking any cash, police said.
Detectives are now focusing on the Netherlands where the three may be living "on a small secluded farm or anonymously in a city, constantly changing from home to home and pretending to be tourists".
"The fugitives are armed and dangerous and should by no means approached when spotted," police said.
The three are among a wider group of fugitives still on the run for membership of the anti-capitalist RAF, also known as the Baader-Meinhof gang, which emerged out of the radicalised fringe of the 1960s student protest movement.
The group, which had links to Middle Eastern militant organisations, declared itself disbanded in 1998.
Staub, Garweg and Klette, alleged members of the RAF's so-called "third generation" active during the 1980s and 1990s, are chief suspects in a 1993 explosives attack against a prison under construction in Germany's Hesse state.
In the attack, five RAF members climbed the prison walls, tied up and abducted the guards in a van, then returned to set off explosions that caused about 600,000 euros worth of property damage, said German prosecutors.
Klette is also a suspect in two previous RAF operations.