Pakistan's top lawyers launched a nationwide strike on Tuesday, a day after a suicide attack on a large crowd of their colleagues killed at least 70 people in Balochistan.

As the country mourned the victims, which included many lawyers and two cameramen who were gathered at a hospital to pay respects to another lawyer who had been shot dead hours earlier, the lawyers said they would boycott court proceedings in much of the country.

Monday's attack at a hospital in the southwestern city of Quetta was one of the worst in the country's long battle against such violence.

Both a Pakistani Taliban faction - Jammat-ul-Ahrar (JuA) - and the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) have claimed responsibility for the attack.

OPINION: Understanding the context of Quetta attack in Pakistan

Some 200 lawyers, along with journalists, had gathered at the Civil Hospital to mourn the fatal shooting of a top provincial lawyer - Bilal Anwar Kasi, with witnesses describing horrific scenes as medics battled to save scores of wounded people.

"Lawyers throughout the country will boycott court proceedings on Tuesday in protest against the killing of lawyers in Quetta yesterday," said a statement from the Pakistan Bar Council, adding that provincial and district bar councils would follow suit.

'Mourn the loss'

Balochistan government spokesman Anwar-ul-Haq Kakar said schools in the province would also be closed on Tuesday "to mourn the loss".

Funerals have already been held for many of the victims, he said.

"Those who were living in and close to Quetta city have already buried their loved ones, while those belonging to far-flung areas will be buried today," he told the AFP news agency.

On Monday officials had put the number of wounded at 112. Twenty-seven of the critically injured were airlifted to Karachi, where a spokesman for the Aga Khan Hospital said they were "out of danger now".

Scores killed in Pakistan hospital suicide bombing

The JuA Taliban faction, which formed in 2014, also claimed responsibility for Pakistan's worst blast so far this year, a bombing in a crowded Lahore park during Easter that killed 75, among other attacks.

The US State Department designated JuA as a terrorist group last week in a statement that described it as "a splinter group of the Tehreek-e-Taliban Pakistan (TTP) based in the Afghanistan-Pakistan border region".

Hours after the JuA claim, ISIL also claimed the attack, according to the SITE monitoring group.

ISIL has been scrabbling for purchase in Pakistan, largely due to competition from well-established armed groups such as the Taliban.

Balochistan, which borders Iran and Afghanistan, has major oil and gas resources, but is afflicted by conflict, sectarian violence between Sunni and Shiite Muslims and a separatist rebellion.

In a tweet, Pakistan's army said the attack was "specially targeting CPEC", referring to China's ambitious $46bn project to build an economic corridor through Pakistan.

The China-Pakistan Economic Corridor is set to culminate in the Baloch Arabian Sea port of Gwadar, south of Quetta.

Pakistan's powerful military chief has previously accused India of "openly" challenging CPEC by trying to destabilise Balochistan.

Here are some reactions to the attack on Monday:

Kamila Shamsie, an author, pointed to a thread written by lawyer Barkhudar Khan that many recommended reading to understand the attack

Ban Ki-moon, UN Secretary-General, called the attack "particularly appalling"

Sharmeen Obaid Chinoy, film director

Fatima Bhutto, writer

Hamid Mir, Pakistani journalist for GEO

Maryam Nawaz Sharif, daughter of prime minister Nawaz Sharif 

Asma Jahangir, human rights lawyer in Pakistan

The International Committe of the Red Cross 

Source: Agencies