Ekrem Imamoglu, mayoral candidate of the main opposition Republican People's Party (CHP), speaks during a news conference in Istanbul, Turkey April 1, 2019. REUTERS/Huseyin Aldemir

ISTANBUL (Reuters) - The candidate of the main opposition Republican People’s Party (CHP) in Turkey’s largest city Istanbul is ahead in the vote count against the candidate of President Tayyip Erdogan’s AK Party (AKP), the head of the country’s High Election Board said on Monday.

Sadi Guven told reporters that the CHP’s Ekrem Imamoglu had 4,159,650 votes and the AKP’s Binali Yildirim had 4,131,761 votes. He did not specify which percentage of votes had been counted.

Earlier, Erdogan appeared to concede defeat in Istanbul.