The incident occurred on Tuesday morning after the pacifist Group for a Switzerland without an Army (GSsA) launched a popular initiative to ban Swiss financing of any company that produces arms.
If it gathers the required 100,000 signatures by October 2018, the issue will go to a national referendum.
The text of the initiative demands that institutions such as the Swiss National Bank, foundations and pension funds be banned from investing in the arms industry.
To mark the launch, 86-year-old peace activist Louise Schneider spray-painted ‘Money for weapons kills’ on a billboard surrounding the Swiss National Bank, currently undergoing renovations.
She was promptly arrested by police.