According to reports, many APC supporters were attacked.
Wariths Alawuje, the party's assembly candidate in constituency 2, was present during the attack but escaped.
Wariths confirmed the incident over the phone and promised to keep everyone updated on further developments.
He said: “We were in a meeting with party executives when we heard members of (party name withheld) walking towards our office.
Our people waited, for them to go. Not long after, we saw a top member of the party whispering to another and the next thing, we started hearing gunshots and before we could say jack, many of our people had been injured, cars had been damaged while nearby houses were not spared. Some persons were also killed.”
Oyo is one of the states where the incumbent governor is seeking reelection.