The banned Popular Front of India has for long been accused of involvement in violent acts, "instigating" protests like the one against the Citizenship Amendment Act and having "links" with global terrorist organisations, including ISIS.

The ban came after over 150 people allegedly linked with PFI were detained or arrested in raids across seven states on Tuesday, five days after a similar pan-India crackdown against the 16-year-old group had led to the arrest of over a hundred of its activities and seizure of several dozen properties.

The group was formed on December 19, 2006, with the merger of the Karnataka Forum for Dignity and the National Development Front (NDF).

NDF was formed after the Babri Masjid demolition and subsequent riots in 1993.

Officials said PFI has been under the radar of security agencies for its alleged role in violent protests in different parts of the country against CAA, forced conversions, radicalisation of Muslim youths, money laundering and maintaining links with banned groups.

It has been also accused of killing people associated with organisations espousing other faiths, collecting explosives to target prominent people and places, supporting the Islamic State and destroying public property to strike terror among people.

The NIA, according to the officials, has secured 45 convictions as part of earlier probes against PFI and has charge-sheeted 355 people in these cases.

Last year, Solicitor General Tushar Mehta submitted before the Supreme Court that the central government is in the process of banning PFI, which has already been outlawed in several states, including Jharkhand.

Mehta also claimed that many PFI officer bearers were found associated with the proscribed Students Islamic Movement of India (SIMI).

In January 2018, then Union minister of state for home Kiren Rijiju said his ministry was considering banning PFI under the stringent Unlawful Activities (Prevention) Act.

Following the anti-CAA protests and subsequent violence in December 2019, the Uttar Pradesh government also recommended the Centre ban PFI.

PFI was also accused of being involved in violence in Goa, Gujarat, Rajasthan, Madhya Pradesh, Jharkhand and West Bengal during last Ram Navami.

According to law enforcement agencies, PFI has over 50,000 members and many sympathisers in Kerala.

"The PFI cadre are encouraged to intervene and react even in minor cases against members of the Muslim community. They are also encouraged to act as guardians of Islamic values, thus effectively converting them into moral police.

"Its cadre are given training in martial arts and combat using sticks, knives or swords in their strongholds," says a document prepared by an agency on PFI.

PFI is also accused of receiving funds from its sympathisers, mostly Indians based in the Gulf countries. It has branches in over two dozen states and union territories including Kerala, Karnataka, Tamil Nadu, Uttar Pradesh, Delhi, Gujarat, Rajasthan, Maharashtra, West Bengal, Assam and Manipur.

Intelligence agencies claim that PFI was involved in a series of violent activities, the most sensational being the chopping of the hand of professor T J Joseph for allegedly insulting Prophet Mohammed in a question paper.

The first conviction of PFI came in 2015 when a special court found 13 of its members guilty in this case. The court acquitted 18 others for want of evidence.

The case was initially investigated by the Kerala police but later transferred to NIA by the UPA government.

The Kerala government, in an affidavit before the Kerala High Court in 2012, had submitted that PFI was a "resurrected avatar" of SIMI and had active involvement in multiple murders, mostly of CPI(M) and RSS cadre.

In 2016, another NIA court sentenced 21 PFI cadre to imprisonment for offences charged under various IPC sections, Arms Act, and the UAPA.

The prosecution case was that the accused persons, PFI and activists of its political wing the Social Democratic Party of India organised an arms training camp in Kannur's Narath on April 23, 2013.

The ED has also been probing PFI's "financial links" following charges of fuelling anti-CAA protests, the February 2020 Delhi riots, the alleged conspiracy in the Hathras gangrape and death of a Dalit woman, and a few other cases.

Till now, it has filed two charge sheets against PFI and its office bearers before a PMLA court in Lucknow.

The first charge sheet was filed in February 2021 against PFI and its student wing Campus Front of India on money laundering charges. It has been alleged that its members wanted to "incite communal riots and spread terror" in the aftermath of the 2020 Hathras gang rape case.

In the second charge sheet filed this year, the ED claimed a UAE hotel "served" as a money laundering front of PFI.

The income tax department in March 2021 revoked the tax exemption benefit to PFI on charges that its activities were "not genuine" as required to be undertaken by a legally notified charitable organisation.

While ED is probing PFI over money laundering allegations, police in Kerala, Karnataka, Andhra Pradesh, and Assam have charged it under various IPC sections, including that of waging war and criminal conspiracy against the state.

The central and state agencies have also accused PFI of "stoking communal violence".

Five PFI activists were named by NIA for the murder of RSS worker Rudresh in October 2016 in Bengaluru. PFI activists were reportedly involved in the 2016 communal violence in Karnataka's Shivamoga following a rally by the outfit during which several vehicles were damaged.

Three people were also allegedly stabbed by the PFI activists in which one died. In 2019, NIA filed cases against 18 PFI activists and leaders under the stringent anti-terror law UAPA after members of the outfit allegedly hacked one Ramalingam in Tamil Nadu.

They reportedly had an altercation with Ramalingam after which they hatched a conspiracy to kill him to terrorise people and deter anyone from interfering in the religious propagation activity of PFI and SDPI.

The Delhi and Assam police have also filed charge sheets against PFI activists in connection with the 2020 Delhi riots and Assam violence in the wake of anti-CAA protests.

Last week, NIA said it was investigating 19 cases involving PFI functionaries.

The agency recently took over the probe in an FIR initially registered by the Telangana police in which evidence showed that PFI leaders were involved in funding terror activities, organising a camp for providing arms training and radicalising people to join banned organisations.

The PFI is also accused of organising a camp for imparting training to commit violent and terrorist acts.