Two men detained on suspicion of conducting an arson attack on the editorial offices of a German newspaper in Hamburg over the weekend have been released due to a lack of evidence, police say.

The offices of daily newspaper Hamburger Morgenpost, which had reprinted Charlie Hebdo cartoons of the prophet Mohammed in the wake of the Islamist killing spree in Paris last week, were hit by an arson attack early Sunday.

• Attack at German paper that ran cartoons

Unknown assailants threw stones and an incendiary device at the offices at around 2am local time.

Police in the northern German city said a fire that broke out in the newspaper’s archive room was quickly extinguished and no one was injured.

The suspects, aged 35 and 39, were spotted near the scene and fled police before being detained in a train.

“We were not able to solidify our suspicions through forensic testing,” a police spokeswoman said on Monday.

The Hamburger Morgenpost ran three covers from the French satirical magazine Charlie Hebdo that depicted the prophet Mohammed on its front page.

“This much freedom must be possible!” said the headline of the Hamburg newspaper.

An attack on Wednesday by suspected Islamist gunmen at the Paris offices of Charlie Hebdo left 12 people dead, including four cartoonists.