ISLAMABAD -  The families of two missing bloggers claimed their loved ones were innocent on Wednesday and appealed for their safe return as soon as possible.

A total of five men, who had stood against religious intolerance and at times criticised military, vanished within days of each other earlier this month, sparking fears of a government crackdown.

No group has claimed responsibility for their abduction and security sources have denied involvement.

"People are making this up, it is hearsay," said Mesha Saeed, the wife of Ahmed Waqass Goraya who went missing from Lahore on January 4. "People are saying that Waqass is affiliated (to blasphemy). But the content attributed to Waqass on that page, he would never do that.

"Whatever content is on that page, we condemn it and he is not responsible for any of it.

"I'm just a student, I'm a simple person. I don't understand why are we being trapped like this," she said.

A number of NGOs and observers say the online campaigns are to silence progressive voices and are carefully coordinated. Several liberal online commentators have already closed their social media accounts in the wake of the accusations.

Pakistan is ranked among the world's most dangerous countries for journalists, and reporting critical of the military is considered a major red flag.

Rights groups say activists and journalists often find themselves caught between the country's security establishment and militant groups including the Taliban.

Faraz Haider, brother of Professor Salman Haider, who disappeared from Islamabad on January 6, said the charges were also putting the lives of other family members in danger. "This propaganda does not only impact the people who are already missing, but also, us, their families," he said.

"We are really concerned about this. Keeping in mind the seriousness of such affairs in Pakistan, we are worried that this will surely cause danger for all of us in the future."

Social activist and lawyer Jibran Nasir said a petition has been filed in the Supreme Court and the National Commission of Human Rights (NCHR) for the recovery of the missing bloggers and a halt to the accusations. He said the case had become "a humanitarian crisis".