Pan-India raids are being carried out by anti-terror units of the states and Delhi Special Cell sleuths on Thursday to nab suspected mastermind of the terror module Humaid.
It is alleged that Humaid, a relative of arrested accused Osama, who is a resident of Delhi's Jamia Nagar, was coordinating the entire terror network in India.
The police are also looking for Osama's father Humaid-ur-Rehman. His whereabouts are unknown.
"Last known location of Humaid was in Uttar Pradesh. We are in touch with Uttar Pradesh anti-terror squad and raids are being carried out at various places," said a top IPS officer privy to the probe.
It is alleged that Humaid had sent Osama and Zeeshan Qamar, a resident of Uttar Pradesh's Allahabad, to Muscat in Oman Ato join training in Pakistan.
Once they reached Muscat, Pakistan Inter-Services Intelligence (ISI) took them to Gwadar port through sea routes to get them trained in making explosives and bombs.
Osama and Zeeshan Qamar were imparted the training of making bombs and IEDs and committing arson with the help of daily use items in a town named Jioni which is near Gwadar port of Pakistan.
They were also trained in handling and use of small firearms and AK-47s.
During the interrogation, it was revealed that Osama left for Muscat, Oman in April where he met Zeeshan who had also come from India.
They were joined by 15-16 Bengali-speaking people. They were divided into sub-groups and Zeeshan and Osama were placed in one group.
Over the next few days, after several short sea-journeys, changing boats several times, they were taken to the town Jioni near Gwadar port in Pakistan. There they were received by one Pakistani who took them to a farmhouse in Thatta, Pakistan.
There were three Pakistani nationals in the farmhouse. Two of these, Jabbar and Hamza imparted training to them. Both of them were from the Pakistan Army as they wore military uniforms.
They were imparted training in making bombs and IEDs and committing arson with the help of items of daily use. They were also trained in handling and use of small firearms and AK-47s.
The training lasted for almost 15 days and thereafter, they were taken back to Muscat through the same route.
Apart from Osama and Zeeshan, the other four arrested accused terrorists have been identified as Jaan Mohammad Shaikh, resident of Maharashtra's Mumbai, Moolchand, resident of UP's Rae Bareilly, Mohd Abu Bakar resident of UP's Behraich and Mohd Amir Javed resident of UP's Lucknow.
All the accused are in police custody for 14 days.
According to conspiracy, the arrested persons were tasked separately to execute different aspects of the terror plan.
The special cell sleuths busted the terror module after they got a tip-off from the central intelligence agencies about the conspiracy being hatched to carry out terror attacks in different parts of the country.
Thereafter. Special Cell carried out a multi-pronged operation wherein several teams were stationed at Mumbai in Maharashtra and Lucknow, Prayagraj, Rae-Bareilly, Pratapgarh in Uttar Pradesh (UP) simultaneously.
On September 14, on the basis of intelligence gathered through human as well as technical nodes, simultaneous raids were conducted in different states. Initially, underworld operative Jaan Mohd Sheikh was apprehended from near Kota, Rajasthan while he was on his way to Delhi; Osama was apprehended from Okhla, Delhi; Mohd Abu Bakar was apprehended from Sarai Kale Khan, Delhi; Zeeshan was apprehended from Allahabad, UP; Mohd Amir Javed was apprehended from Lucknow, UP and Moolchand was apprehended from Rae Bareilly, UP. The operation in UP was done in close and successful coordination with officers of the Uttar Pradesh ATS.
Interrogation has revealed that this module had received sophisticated RDX based IEDs, grenades, pistols and cartridges from a sleeper cell operative and these were sent to UP for safe concealment. The police are looking for sleeper cell operatives who are still in hiding.
During the probe it was found, underworld operative Jaan Mohd Sheikh along with Moolchand were tasked by Pakistan-based Anees Ibrahim, the brother of Dawood Ibrahim, to receive the same in Delhi.
The same was to be handed over to other terror operatives in Delhi and Mumbai and other parts of the country.
Subsequently, further deliveries of similar consignments of IEDs were to be done through the same channel.
The underworld component acting at the behest of Pakistan-ISI was entrusted with two tasks that are the transportation of arms and explosives and terror funding through Hawala channels.
The Pak-ISI trained terror component was tasked with reconnaissance of targets and planting of the IEDs.
Further nodes of this network are being identified, the police said.