Thousands of protesters marched through the streets of the Guatemalan capital on Tuesday to demand the resignation of President Jimmy Morales, whose popularity has dropped since his brother and elder son were caught up in a graft investigation.

Jimmy Morales, a former comedian, was elected president in 2015 on pledges to clean up Guatemalan politics. He came to power after protests over a widespread corruption scandal that toppled his predecessor, retired General Otto Perez, who remains in jail.

The predominantly rural protesters, who headed to the main Constitution square, said they had been tricked by Morales.

Guatemala's President-elect Jimmy Morales FILE - Guatemala's President-elect Jimmy Morales speaks during a interview with Reuters, Guatemala City, Oct. 26, 2015. FILE - Guatemala's President-elect Jimmy Morales speaks during a interview with Reuters, Guatemala City, Oct. 26, 2015.

"About a year ago, Jimmy Morales won with his slogan, 'Neither Corrupt, nor a Thief,'" said Estuardo Batz, one of the leaders of the march called by the Committee of Rural Development. "He lied to us, so he has to go."

There was no official tally of the protesters, but a Reuters reporter estimated the crowd size at about 15,000.

In September, a judge barred Morales' older brother and adviser, Samuel "Sammy" Morales, and son, Jose Manuel Morales, from leaving the country, pending an investigation into suspicious payments linked to the mother of Jose Manuel's girlfriend in 2013.

In January, both were arrested. They say they are innocent.

At the time, Morales said he would support his family, but also respect the law.

Last month, speaking at an event at the presidential palace, Morales rejected rumors of a possible coup, but gave no details and left the event without taking questions.

Morales, who had a 71 percent approval rating in January 2016, had a 56 percent approval rating in January this year, according to a CIG/Gallup poll.