Investigations into the serial blasts in Delhi [Images] indicated linkage of Muzaffarabad in PoK to the incident and Pakistan-based  Lashker-e-Tayiba is a strong suspect irrespective of its denial, police sources said in New Delhi on Wednesday.

At least four terrorists were involved in triggering the three blasts in the national capital in quick succession on
Saturday that killed 59 people and injured 210.

• Complete Coverage: Terror strikes Delhi

Immediately after the third blast at Govindpuri in South Delhi, a call was made from a mobile phone from the area at around 6.05 PM to another mobile phone in Srinagar [Images], the sources told PTI.

The mobile phone, which received the call in Srinagar, was immediately used to make a call to Muzaffarabad in Pakistan-occupied Kashmir, they said.

•  Police investigating UP link?

Investigators believe that the call from Delhi was made by the terrorist to inform about accomplishment of the task of triggering blasts to his master in Srinagar who, in turn, conveyed the message to a 'bigger master' based in Muzaffarabad.

The sources said the phones used in Srinagar and Muzaffarabad were believed to belong to LeT.

Several calls were made to the mobile phone, suspected to be used by terrorists in Delhi, from Saharanpur in western Uttar Pradesh [Images] both before and after the blasts, the sources said.

Calls were made from Delhi to Saharanpur as well, they said.

The terrorists stationed in Delhi received calls from Srinagar from a particular mobile phone a day prior to the blasts.

These calls are believed to have been made to instruct the module in the capital to carry out the blasts, the sources said.

Investigators believe that an elusive LeT commander, based in India identified as Salar alias Hamid alias Afaq, could be
connected with the explosions.

Salar, whose name first appeared in connection with a terrorist act in 1993, is said to maintain continuous mobility, particularly between Saharanpur and Hyderabad.     

He is suspected to be enjoying political patronage in Uttar Pradesh.