A large group of self-proclaimed anti-jihadis rushed the ministry after the introduction of an anti-hate speech law. Police quashed the assault as protesters unfurled banners against "thought police."
A group of 50 members of the Identitarian Movement attempted to storm the Justice Ministry in Berlin on Friday, German media reported.
The group drove a rental truck toward the building, narrowly missing an official. People then took a 10-meter (32-foot) ladder and tried to climb onto the roof of the ministry, while throwing pyrotechnics, a police spokesperson told national daily "Die Welt".
"They were driving a truck, with a big ladder on it and wanted to enter the ministry," an eyewitness told the paper.
Earlier, an unannounced demonstration called for Justice Minister Heiko Maas to step down and for the borders of the European Union to be strengthened, with some participants wearing uniforms in the style of the former East Germany's People's Police.
Witnesses posted images of the protest on social media.
Police managed to stop the rush, and the leader of the group was arrested.
A few hours later, a group of 20 protesters remained outside the barricaded ministry, erecting a banner criticizing the prohibition of opinion.
The act would require social media networks to remove hate speech more consistently.
Maas has been a frequent target of right-wing groups for his stance against right-wing extremism.
A spontaneous counter-Nazi protest group assembled on the other side of the road.
In March the head of Germany's domestic intelligence service warned that the Identitarian Movement was becoming increasingly radicalized.
"There are several indications of contacts and intertwining of the Identitarians with far-right people or groups, so that we are working on the assumption that there is a far-right influence," Hans-Georg Maassen told Funke Media Group newspapers.
This "increasing radicalization," he added, was likely to take the form of spontaneous, provocative actions aimed at political parties, mosques, and Islamic cultural centers or homes for asylum applicants.
Germany's intelligence agencies closely monitor the movement and noticed increased activity among its 300 members. (The group claims to have 500 members.)
Identitarian activists have mounted high-profile publicity stunts in recent months - most famously, a handful scaled the Brandenburg Gate in Berlin on August 27 as the government was holding an open day, and hung a banner on the monument that read: "Secure borders, secure future."