At least 28 people were killed on Wednesday by two separate bomb blasts outside the offices of election candidates in southwestern Pakistan, on the eve of a national vote marred by violence and allegations of pre-poll rigging. More than half a million security officers were deploying ahead of Thursday’s election, with authorities distributing ballot papers to more than 90,000 polling stations. There have been multiple security incidents in the run-up to the vote, with at least two candidates shot dead and dozens more targeted in attacks across the country. “The aim of today’s blasts was to sab…