Former Maharashtra Chief Minister Ashok Chavan on Thursday urged Home Minister Rajnath Singh to act against those who issued threats to journalists Rajdeep Sardesai of India Today and Ravish Kumar of NDTV India.

In a letter to Singh, Chavan said Sardesai and Kumar had been expressing their views in a democratic manner but were being threatened by social media users who did not agree with them. The Lok Sabha MP urged the home minister to ensure that they were not harmed and to take action against the “fanatically minded” who issued such threats.

“This is an extremely dangerous trend, directly attacking the fourth pillar of our democracy, particularly in view of the assassinations of rationalists like Dr Narendra Dabholkar, MM Kalburgi, Govind Pansare and Gauri Lankesh,” the Congress MP wrote.

Chavan said the murders of progressive thinkers was a “shameful chapter” in Indian history for every elected representative. “Silencing their voice by such threats is unacceptable and must be dealt with, going beyond party lines,” he said.

Meanwhile, Nationalist Congress Party leader Supriya Sule also wrote to Singh, expressing concern over the alleged threats, IANS reported.

On September 22, Kumar had posted screenshots of messages that he had received on messaging platform WhatsApp. He had claimed he was repeatedly added to a WhatsApp group on which he was abused. “I’m sad you are alive” was among the messages he said he had received.

At least four journalists in Delhi and Noida have filed police complaints, saying they had received death threats on WhatsApp over the past two weeks. The police have yet to identify the perpetrators.

The identical threatening messages they said they had received referred to the murder of journalist Gauri Lankesh in Bengaluru on September 5 and warned them that they will not be spared if they criticised the Narendra Modi government, the Bharatiya Janata Party or the Rashtriya Swayamsevak Sangh.