With the nation still reeling from the assassination of former leader Shinzo Abe, voters took to the polls Sunday in an Upper House election tipped to determine if Prime Minister Fumio Kishida can win the mandate he needs to push forward with his agenda in the coming years.

Abe was gunned down while on the campaign trail in the city of Nara on Friday. The incident, which has shocked observers both inside and outside Japan, may affect voting behavior, and it is yet to be determined if this will exert a telling effect over the outcome of the election.

Voter turnout as of 4 p.m. stood at 23.01%, according to the internal affairs ministry.