Delhi Police chief Rakesh Asthana said the design and component of the explosives were same.
The Delhi Police investigating the recoveries of IEDs in Ghazipur and Old Seemapuri has found that the design and component of the explosives were same and that a stolen motorcycle was parked near both the spots.
Investigators believe that the same persons were behind planting the IEDs within a month of each other. The sketches of two suspects who claimed to be students hailing from Uttar Pradesh have been prepared, a senior police officer said, adding that efforts are being made to identify and nab them at the earliest.
The explosives recovered at the two spots in Delhi were similar in make and design to those that were recovered from Punjab two months ago, police said.
"Though the explosives recovered from Punjab and Delhi's Old Seemapuri and Ghazipur were of similar make and design, those recovered in Punjab were explosives of lightweight and those in Delhi have a metallic covering," the officer said.
Another officer said "we cannot rule out the possibility of the involvement of Pakistan's ISI which might have made such sophisticated design and sent it to Punjab and Delhi." The investigators are looking into it, the officer added.
According to the police, the owner of the house in Old Seemapuri where the explosive weighing 2.5 to 3 kg was found and a property dealer were being questioned.
The sketches of suspects prepared are of two people who told the house owner that they were students and hailed from Uttar Pradesh.
The two suspects stayed at the house for the last two months. The house owner had claimed during interrogation that he had collected their identity proofs but the police said they were yet to recover any of it.
The IEDs found in the Old Seemapuri house on Thursday and in the Ghazipur flower market on January 17 were prepared with the intention of carrying out blasts at public places across the city, Delhi Police Commissioner Rakesh Asthana had said on Friday.
Such activities are not possible without local support, he had added.
The investigation revealed that both IEDs were made with a mix of ammonium nitrate and RDX, the senior police officer said. Both explosives were defused in a controlled manner and no one was injured.
In a CCTV footage collected from near the Ghazipur spot, a black Hero Splendor motorcycle was seen parked nearby.
And after the IED recovery in Old Seemapuri, the police recovered a similar motorcycle from near Dilshad Garden Metro Station. It was found to be stolen and investigators believe it is the same motorcycle seen in the CCTV footage collected from the Ghazipur spot.
The recovery of the IED at the Ghazipur flower market came ahead of Republic Day celebrations on January 26 for which the security apparatus in the national capital was on high alert.
Delhi Police chief Asthana earlier said the Special Cell and other teams were investigating the case.
The investigators are probing forward and backward linkages. "We are trying to pre-empt every such incident in Delhi and expose any local and foreign network," he added.
Officials from the National Investigation Agency and the Uttar Pradesh Anti-Terrorist Squad had on Friday visited the scene of crime in Old Seemapuri as multiple agencies have been working on the case.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)