A man has died after being hit by a bus in Dublin city.
Gardai are investigating the incident, which reportedly occurred after an altercation at the junction of Dawson Street and Nassau Street.
The accident happened at 5.40pm.
A Garda forensic examination of the scene was launched after the man was found to have died.
Dublin Bus, which diverted services away from the area, said more than a dozen routes would be delayed.
"Dublin Bus wishes to advise customers that, due to an accident on Dawson Street, it is closed to traffic and all buses are being diverted," the company said.
"There was a fatal accident at the junction with Nassau Street at about 5.40pm this evening involving a pedestrian."
The bus was the 145 en route to Heuston railway station.
There were unconfirmed reports that the altercation involved two or three men at the roadside.
A Dublin Bus inspector was at the scene, helping gardai with their investigations.
A spokeswoman for the company said CCTV from the bus would also be used to establish the circumstances of the accident.
A separate Dublin Bus investigation will run alongside the garda inquiry.
The driver of the bus also gave a statement to gardai at the scene.
Motorists were warned to avoid the area as the scene was sealed off for a forensic examination.
Dublin Bus said all services would be experiencing huge delays in the city centre.
AA Roadwatch said both Nassau Street and Dawson Street were closed due to the incident, shutting access routes to St Stephen's Green.
Gardai have appealed for any witnesses to come forward.
It is understood that witnesses reported seeing two men arguing near the junction just before the accident.
Gardai said the victim was in his late 20s.
He was pronounced dead at the scene and no-one else was injured, a spokesman added.
A post-mortem examination is to be carried out and the State Pathologist's office has been notified.
Gardai urged witnesses to contact officers at Pearse Street Garda Station.