At least 70 people were killed and dozens more injured when a suspected suicide attacker blew himself up at a Sufi shrine in Pakistaninfo-icon's southern Sindh province on Thursday, the latest in a string of terror attacks in the country this week.

The explosion occurred at the Lal Shahbaz Qalandar shrine in Sehwan town when a large number of people had gathered for 'dhamaal' (a Sufi ritual), Pakistani mediainfo-icon reported.

Large crowds frequent the famed shrine, which has the mausoleum of Sufi saint Lal Shahbaz Qalandar, on Thursdays.

Pakistani news channels quoted medical officials as saying at least 70 people were killed and state-run Radioinfo-icon Pakistan said the death toll could rise as several of the injured were in critical condition. The wounded were taken to nearby hospitals and a large police contingent was deployed at the site.

Armed forces aid in rescue efforts

Chief of Armyinfo-icon Staff General Qamar Javed Bajwa, following the attack, directed that immediate assistance be provided to civil authorities. Army contingents were dispatched along with medical personnel. Combined Military Hospital Hyderabad was also alerted to receive casualties.

Air evacuation of the injured was started from Nawabshah airport, the armed forces had tasked a C-130 aircraft and helicopters to aid in the effort. The injured were taken to Karachi and Hyderabad, the Inter-Services Public Relations (ISPR) said.

The ISPR added that the armed forces had placed all required resources to facilitate the rescue effort. Pakistan Army and Rangers assisted with rescue efforts at the site.

The chief of naval staff placed all navy hospitals in Karachi on high alert. The air force also placed its hospitals on alert to treat the injured.

Chief Minister Sindh Syed Murad Ali Shah had directed all rescue teams to reach the spot of the attack.

 "Doctors from Jamshoro, Nawabshah and Hyderabad were sent to Sehwan," Shah told DawnNews. He also said security has been tightened at all shrines across the province. Sehwan is Shah's constituency.

A mobile forensic van of the Sindh Police was dispatched to the shrine following the attack.

Condemnations Pour In

Pakistan Tehreek-i-Insaf Chairman Imran Khaninfo-icon condemned the suicide blast and said he was shocked and saddened on the terrorist attack which targeted innocent people, including women and children.

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Interior Minister Chaudhry Nisar Ali Khan also strongly condemned the blast at Sehwan. He expressed deep sorrow over the loss of precious lives and sympathised with the bereaved families.

Chairman PPP Bilawal Bhutto-Zardari said the terrorist attack on the shrine in Sehwan was the worst form of terrorism aimed at ripping apart the Sufi fabric of unity and peace.

"This was an attack on our culture, historyinfo-icon and civilisation. Every single individual of this land will fight against the terrorists and uproot this menace, said the PPP scion adding that the perpetrators will be brought to justice.

Resurgence In Terror Attacks

Pakistan seems to be experiencing a fresh resurgence in terror attacks.

Earlier today, an explosive device had targeted an Army convoy in the Awaran area of Balochistaninfo-icon, killing three soldiers.

On Feb 15, a suicide bomber struck in Mohmand, killing three personnel of the Khasadar force and five civilians. The attack was claimed by Tehreek-i-Taliban (TTP)

The same day, a suicide bomber rammed his motorcycle into a vehicle carrying judges in Peshawar's Hayatabad Phase 5 area, killing the driver and injuring its four other occupants. The attack was claimed by the TTP too.

On Feb 13, a suicide bomber had struck a protest on Lahore's Charing Cross interchange, killing 13 and injuring 85. The attack had happened right outside the gates of Punjab's Provincial Assembly.

The attack was claimed by the Jamaat-ul-Ahrar.

On the same day, two personnel of Balochistan's bomb disposal squad were killed as they attempted to defuse an explosive device planted under the Sariab Road bridge in Quetta, the provincial capital.

The last attack on a shrine of a Sufi mystic took place on November 12, 2016, when a suicide bomber struck the shrine of Shah Norani in the Khuzdar district of Balochistan, where at least 52 people were killed and 102 were injured.

The explosion had also taken place at a spot inside the Shah Noorani shrine where the dhamaal was being performed. At the time of the blast, there were at least 500 people gathered at the spot to observe the ritual.

IS Claims Responsibility For Attack

The ISIS claimed responsibility for the attack on their Aamaq news agency, saying a suicide bomber had targeted a "Shiite gathering" at the shrine in Sindh.

25 killed in crackdown after attack 

A nationwide security crackdown was launched on Friday, officials said, after a bomb ripped through a crowded shrine of Lal Shahbaz Qalandar in Sehwan.

"Both the federal and provincial law enforcement authorities and police started a crackdown across the country before dawn, and scores of suspects have been arrested from different cities," a government official speaking on condition of anonymity told AFP.

He said the sweeping operation will continue for the coming days.

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A statement from the paramilitary Rangers said at least 18 militants had been killed in operations in Sindh overnight, while police officials said 11 more had been killed in Khyber Pakhtunkhwa.

Three alleged militants were killed during a search and strike operation in Reggi area of Peshawar. According to officials, weaponsinfo-icon and hand-grenades were also recovered from the militants.

Security sources said four terrorists were killed in an exchange of fire with security forces after they attempted to attack a security check-post in Orakzai Agency. Four more were killed in Bannu during an exchange of fire.

Prime Minister Nawaz Sharifinfo-icon and army chief Gen Qamar Bajwa have vowed to fight the new wave of terrorism, which broke a relative lull across the country in recent months. The manner in which the attacks are taking place suggests that the country's fight against terrorism is not yielding results.