"The intelligence agencies are making progress to unearth networks behind the recent terrorism incidents," read a statement issued by the Inter-Services Public Relations.
Pakistan-Afghanistan border closed:
In its statement, the military claimed that it had found linkages to militant support networks operating from across the border.
"The border has been closed since last night due to security reasons. No cross-border or unauthorised entry will be allowed into Pakistan from Afghanistan," read the statement.
The security forces have been given special orders to maintain strict vigilance all along the border, it added.
"The Army is for security of people of Pakistan against all types of threat. The nation should stay steadfast with full confidence in their security forces. We shall not let the hostile agenda succeed whatever it may cost," army chief General Qamar Javed Bajwa was quoted as saying.
Devotees were performing 'Dhamal' at the time attack took place:
The white marble floor at the shrine was still marked by blood and a pile of abandoned shoes and slippers was heaped in the courtyard, many of them belonging to victims.
The devotees performed 'Dhamal', a spiritual dance, after the sunset prayer. Lal Shahbaz Qalandar was a Sufi philosopher-poet of present-day Afghanistan and Pakistan.
Attackers came dressed in Burqa:
Initial investigations said that there was no proper electricity at the shrine when the attack took place.
"Investigations point to the fact that the attacker came dressed in a Burqa and entered the shrine from the golden gate amidst the heavy crowd of devotees," DIG Hyderabad range Manzoor Rind said.
Hyderabad is the largest city closest to the town of Sehwan where the shrine was attacked.