India, March 9 -- Colombians head to the polls on Sunday to elect a new Congress and select candidates from three major coalitions in a primary-style contest ahead of a presidential election this May.

The election unfolds under high alert for political violence across the South American country, particularly in rural regions dominated by illegal armed groups.

At the same time, President Gustavo Petro - the nation's first left-leaning leader - has cast doubt on the country's election software, pointing to the 2022 legislative elections, when his Historic Pact movement gained over 390,000 votes following a recount.

He attributed this shift to the presence of election observers.

The European Union deployed 40 election observers in early ...