The campaign of presidential candidate Hamdeen Sabahi withdrew all its delegates from polling stations on Wednesday on the third day of Egypt's presidential election.
The Presidential Elections Commission supervising the election extended the vote for an extra day on Wednesday.
Both Sabahi and his contender, former army chief Abdel Fattah al-Sisi, have criticized the extension and filed official complaints to the commission.
Sabahi's campaign said in a statement earlier on Wednesday that some of its members were attacked while trying to expose violations.
The violations included being prevented by police and army forces from entering polling stations, being kicked out while observing the electoral process and being arrested and attacked, the statement explained.
The campaign said it filed official reports to the PEC, but received no response.
