Germany's Interior Ministry has banned an internet site on allegations it was being used to foment left-wing extremist violence, including at this summer's G-20 summit.

Interior Minister Thomas de Maiziere said Friday the site "linksunten.indymedia.org" was responsible for mobilizing "violent actions and attacks on infrastructure" targets. Among other things, he says the site provided information on how to build gasoline bombs and other incendiary devices with timers.

The ban comes less than two months since the G-20 summit in Hamburg, which saw three nights of violence.

In conjunction with the ban, police searched multiple premises used by people connected to the site.

The Interior Ministry last year banned a far-right site on similar allegations.

De Maiziere says "there's no place for radical, violence-prone extremism in our society from any side."