A series of bombings in different parts of Pakistan killed 103 people on Thursday, including 69 who died in a sectarian attack on a bustling billiard hall in the southwest city of Quetta, officials said.

The blasts punctuated one of the deadliest days in recent years in Pakistan, where the government faces a bloody insurgency by Taliban militants in the northwest and Baluch militants in the southwest.

The country is also home to many enemies of the U.S. that Washington has frequently targeted with drone attacks. A U.S. missile strike Thursday killed five suspected militants in the seventh such attack in two weeks, Pakistani intelligence officials said.

The billiard hall in Quetta, the capital of Baluchistan province, was hit by twin blasts about 10 minutes apart on Thursday night, killing 81 people and wounding more 120 others, said senior police officer Hamid Shakeel.

Pakistani security officials examine the site of a bomb attack in Quetta on Thursday that killed 12 people and wounded more than 40 others. (Banaras Khan/Agence France-Presse/Getty Images)

The billiard hall was located in an area dominated by Shia Muslims, and most of the dead and wounded were from the minority sect, said another police officer, Mohammed Murtaza. Many of the people who rushed to the scene after the first blast and were hit by the second bomb, which caused the roof of the building to collapse, he said.

Police officers, journalists and rescue workers who responded to the initial explosion were also among the dead, police said.

The sectarian militant group Lashkar-e-Jhangvi claimed responsibility for the attack to local journalists. One of the group's spokesmen, Bakar Saddiq, said the first blast was carried out by a suicide bomber and the second was a bomb planted in a car and detonated by remote control.

Attack in commercial area

Radical Sunnis groups often target Pakistan's Shia minority, whom they believe hold heretical views and are not true Muslims.

Canada's Foreign Affairs Minister, John Baird, issued a strong condemnation.

"This type of violent extremism is entirely despicable," he said in a statement. "It is a stark reminder that the greatest threat to Pakistan is terrorist entities operating within its borders."

A spokesperson for UN secretary-general Ban Ki-moon said he was "deeply concerned" by the ongoing violence in Pakistan. "He reiterates the strong support of the United Nations for the efforts of the Government of Pakistan to combat the scourge of terrorism and hopes that the perpetrators of these violent acts will be brought to justice," said a statement.

Earlier in the day, a bomb targeting paramilitary soldiers in a commercial area in Quetta killed 12 people and wounded more than 40 others, said Shakeel, the senior police officer.

The United Baluch Army, a separatist group, claimed responsibility for the attack on the soldiers in calls to local journalists.

Elsewhere in Pakistan, a bomb in a crowded Sunni mosque in the northwest city of Mingora killed 22 people and wounded more than 70, said senior police officer Akhtar Hayyat.

No group claimed responsibility for the attack.

With files from CBC News