The president's office said a man was detained but denied a shoe was thrown
A man has thrown a shoe at Sudanese President Omar al-Bashir during a public meeting, according to witnesses.
He missed his intended target, but witnesses said he was immediately arrested by security staff in Khartoum.
The president's office denied the shoe incident but said officers detained a man trying to give a note to Mr Bashir.
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.
No reason was given for the reported attack on Mr Bashir, who is wanted on an international arrest warrant for alleged war crimes committed during in Sudan's Darfur region.
He is seeking re-election in April - the country's first multi-party polls since 1986. Tensions are rising ahead of the election, especially.
One eye-witness told Reuters news agency: "The man was close to the podium and threw the shoe but it didn't reach him."
Witnesses told the agency the man was smartly dressed, aged in his 40s or 50s and said nothing during the incident.
"He seemed calm, even after he was arrested," said another witness.
Presidential spokesman Emad Sidahmed told Reuters the man "just wanted to give the president a note ... but was intercepted by the security".
The witnesses said they had been attending a conference on strategic planning in Khartoum's Friendship Hall.