Islamabad, Pakistan (CNN) -- The death toll climbed to 50 on Friday after a pair of suicide bombers detonated their explosive vests at one of Pakistan's holiest shrines, police said.

More than 200 people were injured in the blasts outside the Data Darbar, a famous Sufi shrine complex.

Lahore Commissioner Khusro Pervez said the remains of the bombers -- a man in his 20s and another in his late teens -- have been recovered.

One of the bombs detonated in the shrine's courtyard; the other in the shrine's lower lever, according to Chaudhry Shafiq Ahmed, Lahore's senior police superintendent. The first explosion, which occurred at 10:48 p.m. Thursday, was followed five minutes later by a second blast, Geo TV reported.

The CNN affiliate aired surveillance footage showing the first attacker entering through a gate holding a bag. As he passed through a metal detector, alarms went off and the man ran toward an area used for ablutions and blew himself up.

Geo TV showed a second attacker entering amid the confusion a few minutes later and running upstairs carrying a bag. Then the video showed the explosion.

Geo TV reported that the heads of two bombers were recovered and identified. The bombers arrived at the shrine on foot wearing 10 kilogram (22 pound) jackets that had been packed with ball bearings, it said.

A witness told Geo TV that one of the bombers was wearing the traditional loose-fitting salwar kameez, a turban and slippers.

"This sickening poison of extremism will be driven out of our nation and we will not be cowed," said Farahnaz Ispahani, a spokeswoman for President Asif Ali Zardari, in a text message to CNN.

"Peaceful worshippers have once again been targeted by those who want to destroy the fabric of this great country. We will not forgive or forget and we will get justice for all Pakistanis murdered in cold blood -- be they Muslim, Christian, Ahmadi or of any other faith."

Pakistan's Punjab province, of which Lahore is the capital, has been the scene of carnage in recent weeks, including a bloody attack on a hospital and another targeting Ahmadis.

On Friday, angry Pakistanis, some wielding guns for revenge, took to the streets of Lahore in protest. Growing weary of bloodshed in their homeland, many are troubled by its spread from the Afghan border areas to the heartland. They are also concerned that Muslims are attacking Islamic holy sites.

Sunni and Shiites do not consider the Ahmadis as a part of Islam because they do not regard Mohammed as the last prophet sent by God. As such, they have been targeted by Islamic extremists.

Friday's attack was at a revered Sufi shrine. Sufism is an ancient, mystical form of Islam that is generally more tolerant.

The Human Rights Commission of Pakistan expressed alarm over the attacks and called on both the government and Muslim clerics to stand up to extremism.

"It is a matter of grave concern that despite repeated official claims of breaking the back of terrorists, they retain the ability to launch vicious terrorist attacks across the country almost at will," the commission said in a statement Friday.

"The assault demonstrates the potency of militant groups that the government incessantly repeats operate from sanctuaries in the tribal areas bordering Afghanistan," the statement said. "Equally frustrating have been clerics' stock statement that no Muslim can commit such atrocities. Instead of living in denial, the clerics need to reflect on the reasons for religious extremism in Pakistan and the possible consequences and their own contribution to the promotion of intolerance and the cult of violence."

CNN's Nasir Habib, Nic Robertson, Nazneen Akbari, Thomas Evans, Katy Byron and Journalist Fayyaz Addrees contributed to this report.