Two blasts took place near electoral candidates' offices in Pakistan's southwestern province of Balochistan, local officials said on Wednesday.
In the first incident, at least 12 people were killed at the office of an independent candidate in Pishin district. A second explosion left 10 people dead in Qilla Saifullah, a town near the Afghan border.
Khanzai Hospital, close to the first blast site in Pishin, treated numerous casualties, some with serious injuries.
The religious party has previously been the target of militant attacks. In July last year, 44 people were killed by a suicide bomber at a political gathering of the party in northwestern Khyber Pakhtunkhwa province.
Balochistan has been the target of multiple groups of Islamist militants, including the Pakistani Taliban and the "Islamic State" militia. Separatist rebels have also been launching deadly attacks on the security forces and civilians.
Pakistan going to the polls
The explosions come a day ahead of the country's general election.
Pakistan's 127 million voters get to elect a new parliament on Thursday that will choose a new prime minister after the vote.
Authorities have said they are boosting security at polling booths following Wednesday's blasts.
More than half a million security officers have already been deployed to ensure peace following a surge in militant attacks.
The Pakistan Institute for Conflict and Security Studies, an Islamabad-based think tank, said there had been a "staggering" rise in militant attacks in the past year with an average of 54 per month -- the most since 2015, when the army launched a massive crackdown on militant groups.
Political parties have completed their campaigns and are now observing a quiet period leading up to the election as required by electoral regulations.