Shops and offices were shut in the eastern Pakistani city of Lahore on Saturday in a protest strike over suicide attacks on an Islamic shrine, which killed 43 people.
Police said they have "apprehended" several people in their investigation into Thursday's bombings, which left a trail of carnage at a packed Sufi shrine, but have made no formal arrests.
Police also said they had uncovered 20 suicide bombing vests and two dozen police commando uniforms during a raid in Lahore late Friday.
Angry protesters had taken to the streets in Pakistan on Friday, burning tyres and blaming Taliban extremists for the latest bloodshed in the city, a major military, political and cultural hub.
Raghib Naeemi, a leader of a Sunni Muslim council that called the strike, said a major rally was being planned on Saturday evening.
"We will continue our protest till the government takes some concrete actions to curb terrorist activities," he said.
Investigators said they had yet to identify the two suicide bombers who blew themselves up among crowds of worshippers at the shrine to Sufi saint Data Ganj Bakhsh in Lahore, capital of Punjab province.
There was no immediate claim of responsibility for Thursday's bombings and the Pakistan Taliban, which has been blamed for a wave of bloody attacks over the past three years, denied it was involved.