An FIR has been registered here against an unidentified person for posting controversial pictures containing alleged derogatory references to warrior king Shivaji and the late Shiv Sena leader Bal Thackeray on social networking site Facebook, police said today.

Also read: Scared of Sena mob, cop arrested girls over Facebook post

Bal Thackeray
The late Shiv Sena supremo Bal Thackeray

The FIR was registered against the person last night under IPC section 295A (deliberate and malicious acts, intended to outrage religious feelings of any class by insulting its religion or religious beliefs) and relevant sections of the IT Act, an official at Mulund Police Station told PTI.

After spotting the Facebook posts which contained the alleged derogatory references, Shiv Sena activist Avinash Bagal complained at the police station yesterday.

According to sources, Cyber Cell of the Mumbai police had, with the help of Facebook administration, blocked one account which contained objectionable pictures last night.

However, a second Facebook account had been created by an unidentified person which was also blocked by police with the help of social networking site.

Shiv Sainiks staged protests in Pune and its surrounding localities last night and this morning and pelted stones at buses irked over the Facebook posts.

About eight buses were damaged in the incidents as the Sena activists took to the streets.

In 2012, two girls were arrested over a controversial Facebook post on late Bal Thackeray.