President Bashir is considered likely to be re-elected in April
A man has thrown a shoe at Sudanese President Omar al-Bashir while he was making a public speech in Khartoum.
He missed his intended target and was immediately arrested by security staff.
Sudan's official news agency reports that the man, Adel Mahjoub, suffers from severe psychological problems and denies any political motive.
Mr Bashir is wanted for alleged war crimes in Darfur and is seeking re-election in April. Throwing shoes is hugely insulting in Arab culture.
Former US President George W Bush had shoes hurled at him during a visit to Iraq in 2008.
Mr Mahjoub wanted to hand a list of grievances to Mr Bashir but was prevented from doing so by security agents, reports the official Suna news agency.
The man, described as smartly dressed and in his 50s, then grew angry and threw his shoe at the president.
One eyewitness told Reuters news agency: "The man was close to the podium and threw the shoe but it didn't reach him."
"He seemed calm, even after he was arrested," said another witness.
The witnesses said they had been attending a conference on strategic planning in Khartoum's Friendship Hall.
The authorities say Mr Mahjoub will be handed over to his family once his psychological treatment is finished.
April's elections are Sudan's first multi-party polls since 1986 and Mr Bashir is favourite to be re-elected despite the international warrant for his arrest.