ISTANBUL • When making a social phone call, you do not expect to hear the voice of the head of state.

But mobile phone users in Turkey were surprised to hear a voice message from President Recep Tayyip Erdogan when they placed a call at around midnight on the anniversary of the failed July 15 coup.

After dialling a number, instead of hearing a dial tone, users heard a voice message from Mr Erdogan congratulating them on the national holiday of "democracy and unity" that marks the coup's defeat.

Only after Mr Erdogan's message did the dial tone begin.

"As President, I send congratulations on the July 15 National Day of Democracy and Unity and wish the martyrs mercy and the heroes (of the defeat of the coup) health and well-being," said the message read by Mr Erdogan.

The message could be heard on Turkey's largest network, Turkcell, AFP correspondents said. The Hurriyet daily said it was also heard on the Vodafone network.

"People who wanted to chat on the telephone got an Erdogan surprise..." said Hurriyet.

Turkcell had already sent text messages to clients, promising them a free extra gigabyte of data from July 15 in celebration of the coup's defeat.

In the wake of the coup bid, users had received text messages from Mr Erdogan. But this is believed to be the first time a voice message has been employed.

"Enough now... you even get it on the phone... how can there be such an insult, it's like a nightmare," opposition lawmaker Aykut Erdogdu wrote on Twitter.

AGENCE FRANCE-PRESSE