Turkish President Recep Tayyip Erdoğan celebrated his election victory Sunday, declaring that “the sufferers of our region and all oppressed in the world” won the election as opposition leaders and international observers decry widespread arrests, ballot irregularities, and censorship.

ISTANBUL, Turkey — Turkish President Recep Tayyip Erdogan won tightly-contested presidential polls, the election authority said Monday, extending his 15-year grip on power as the opposition complained bitterly about the conduct of the vote count.

President Recep Tayyip Erdogan and his main rival Muharrem Ince on Saturday traded blows in mass rallies on the final day of campaigning for Turkey’s most fiercely contested elections in years.