ISTANBUL (AFP) - A Turkish government minister on Tuesday (April 18) blasted the EU's "unacceptable" appeal for a probe into alleged irregularities in the referendum on boosting President Recep Tayyip Erdogan's powers.

"Such a speculative statement from a spokesperson cannot be accepted," Turkey's EU Affairs Minister Omer Celik told reporters at a televised press conference, calling on the EU to "respect democratic processes".

His comments came after Brussels urged Ankara to probe claims of irregularities in Sunday's vote which resulted in a narrow win for the 'Yes' camp on the controversial constitutional changes.

"We call on the Turkish authorities to consider the next steps very carefully, and to seek the broadest possible national consensus in the follow-up to the national referendum," European Commission spokesman Margaritis Schinas said at a press conference in Brussels.

International observers charged Monday that the referendum campaign was conducted on an "unlevel playing field" and that the vote count was marred by late procedural changes that removed key safeguards.

Celik slammed the report by the international observers as "groundless" and "far from maturity".

The OSCE Office for Democratic Institutions and Human Rights (ODIHR) and the Parliamentary Assembly of the Council of Europe (PACE) monitors "exceeded their limits," he said.