An FIR was registered against unidentified person/s for hacking into unsecured WiFi network in Navi Mumbai and allegedly concealing the existence of a design to wage war against India, police said today.

The unidentified person/s were booked yesterday under relevant sections of Information Technology Act and IPC section 123 (concealing with intent to facilitate design to wage war), Rao Sardesai, Senior Inspector at Vashi Police Station in Navi Mumbai, told PTI.

The offence is punishable with imprisonment of up to 10 years and also fine, police said.

The terror outfit Indian Mujahideen (IM) was suspected to have had hacked into WiFi network of Akhil Talreja, a resident of Sector 17 in Vashi and sent the email to media houses, claiming responsibility for the Varanasi blast.

Talreja, a 26-year-old disc jockey, was questioned by police twice but later let him off, saying he was innocent.

Sources in Mumbai Crime Branch said they are sifting through the CCTV footages available with commercial establishments in the Sector 17 to identify if any person was found moving suspiciously in the locality.

According to police, the logger of the router has been disabled, so there was no trace of who logged and hacked it.

The Gmail ID used and the mail was written on December 6. The account has been accessed rarely, police sources said.

The IM had been using unsecured WiFi connections for sending mails to media houses within minutes of blasts.

On Tuesday, a low-intensity blast ripped through a crowded bathing ghat on the banks of the Ganges during evening prayers in Varanasi, killing a child and injuring 37 others, including six foreigners.