A pedestrian is in hospital in serious condition after he was struck in downtown Ottawa early Friday.

Ottawa paramedics said they were called to the area in front of 99 Rideau Street, directly across from the Rideau Centre, just after 3 a.m. Friday.

They said a man in his 20s was found unresponsive after he was thrown over the vehicle that hit him, believed to be an SUV.

His head injuries were originally considered life-threatening but his condition has improved.

Paramedics said he was in critical condition when he arrived at hospital and has since been upgraded to serious.

Ottawa police are investigating the incident and have reopened Rideau Street after it was closed immediately after the collision.