Turkish President Recep Tayyip Erdogan portrayed the decision for a re-run of local elections in Istanbul, where his party suffered a surprise defeat, as a step to strengthen democracy.
Speaking to a parliamentary group of the governing Justice and Development Party, he talked of shadows in the initial procedure which must be removed.
"It became clear that specific people with dirty hands were involved, beginning before the elections and reaching this point, step by step. I honestly believe that this was organised corruption, total lawlessness and unlawfulness in the Istanbul local elections," President Erdogan said
His party and its allies had complained of irregularities that they said affected the outcome. The election board upheld that complaint, and voters in the city will go to the polls again, on June 23.
Ekrem Imamoglu, who was declared the winner of the Istanbul elections and is a candidate with the Republican People's Party, expressed his discomfort about the re-run of elections .
And in protest about the latest developments, residents in many neighborhoods around Istanbul have been banging their pots and pans since Monday night. Some of them went onto the streets to express their dissatisfaction.
Meanwhile, Germany's Minister of Foreign Affairs Heiko Maas has expressed concern, referring to an incomprehensible and non-transparent decision.
Erdogan was not standing in the March 31 local elections, but they were seen as a referendum on his leadership amid an economic crisis and deteriorating relations with Europe.