Left parties on Tuesday hit out at the Union government over the arrest of Alt News co-founder Mohammed Zubair, asking it how those who spread hate are free, and someone who exposes them is behind bars.

Meanwhile, the Delhi Press Club too has asked for the release of the journalist.

The parties have demanded his immediate release.

"Hate-mongers of the right are getting patronage from rulers. So-called fringe elements who brought disrepute to the country are being protected.

"Young journalists like Mohammed Zubair, who are working to protect the scientific temper of the country are behind bars. Condemnable!" said CPI general secretary D Raja on Twitter.

Fact-checking website Alt News co-founder Mohammed Zubair was arrested by the Delhi Police on Monday allegedly for hurting religious sentiments through one of his tweets, officials said.

Alt News co-founder Pratik Sinha alleged that Zubair was arrested in a case for which no notice was given by the police, which is mandatory under law for the sections under which he has been held.

"Nupur 'fringe' Sharma roams free on the fringe away from the 'reach' of the state. Mohammed Zubair who brought her hate speech to the notice of the world is at the centre of the regime's action," tweeted Dipankar Bhattarcharya, general secretary, CPI-Marxist-Leninist.

Zubair on Monday joined the probe in a case registered against him in connection with another tweet in 2020.

During the investigation, the Delhi Police had given a status report, in which that tweet was not found to be objectionable.

His subsequent tweets, however, were found to be questionable and derogatory, the police said, adding that in the investigation of FIR number 194/20, Zubair was examined earlier and the probe is about to be concluded.

"Release @zoo_bear immediately. The Modi government is insecure & threatened by anything that exposes the fake hate machine of misinformation," said CPI-Marxist general secretary Sitaram Yechury in a tweet.