ISTANBUL (REUTERS) - A former Turkish beauty pageant winner may face up to a year in prison over a tweet referring to last year's failed military coup that cost her "Miss Turkey" title, the private Dogan news agency said on Thursday (Dec 7).

An Istanbul prosecutor has indicted 18-year-old Itir Esen, who in September was stripped of her title after one day, for "publicly humiliating a segment of the society" following three official complaints over her tweet, Dogan reported.

On July 16 this year, Esen tweeted: "I had my period on July 15 morning to celebrate the day to commemorate martyrs. As a representation of our martyrs' blood, I am commemorating this day by bleeding."

She later deleted the tweet and deactivated her Twitter account.

Dogan said the indictment included a statement by Esen in which she said her tweet was shared in an ironic way to commemorate those who died on July 15, 2016, and there was no intent to insult any part of Turkish society.

Around 250 people, mostly unarmed civilians, were killed and over 1,000 wounded in the failed coup bid on July 15, 2016. The day was later declared Democracy and National Unity Day and a public holiday in Turkey.

More than 150,000 state employees have been suspended or sacked and over 50,000 have been jailed pending trial in a security crackdown following the attempted coup.

Rights groups and some of Nato-member Turkey's Western allies have voiced disquiet about the crackdown, fearing the government is using the coup as a pretext to quash dissent.