A suicide bomber has killed at least 128 people at a campaign rally in south-western Pakistan - the deadliest attack in the country since 2014.
A local candidate was among the dead in the Mastung town, police say. So-called Islamic State (IS) claimed the attack.
Earlier, a bomb attack on a similar rally in the northern town of Bannu killed four people. The attacks come ahead of general elections on 25 July.
Meanwhile, former PM Nawaz Sharif was arrested after flying home from the UK.
Sharif and his daughter Maryam were taken into custody by officials from the National Accountability Bureau (NAB) after landing in the northern city of Lahore. They were then put on a chartered plane bound for Pakistan's capital Islamabad.
They were later transferred to a local prison.
The three-term PM was ousted last year after a corruption investigation. Last week he was sentenced in absentia to 10 years in prison.
He has accused Pakistan's powerful security establishment of conspiring against him ahead of the elections.
What is known about Friday's attacks?
More than 150 people were injured in Mastung, officials say.
Among those killed was Baluchistan provincial assembly candidate Siraj Raisani, his family said. He was a candidate for the Balochistan Awami party.
Local officials say the attacker detonated a bomb inside a crowded compound where the campaign rally was being held.
"Human remains and red bloody pieces of flesh were littered everywhere in the compound," local journalist Attah Ullah was quoted as saying by the AFP news agency.
"Injured people were crying in pain and fear," the journalist said.
IS militants later used their news outlet to claim the group carried out the attack.
IS has carried out a number of attacks in the region bordering Afghanistan in recent years. However, security has improved since the military managed to clear large swathes of territory.
Friday's bombing was the deadliest attack since militants from the Pakistani Taliban assaulted an army-run school in Peshawar in December 2014, killing 141 people, 132 of them children.
Earlier in the day, a campaign convoy of another candidate was attacked in Bannu.
Akram Khan Durrani, who represents the MMA party, was unhurt, officials say.
No group has so far claimed responsibility for that attack.