Gardaí in Roscrea are investigating the circumstances of a serious road traffic collision on the N7 Dublin to Limerick road yesterday evening.
Two cars were involved in the crash, which took place about two miles outside Roscrea on the Dublin side of the town, at about 7.30 pm.
In one car there were two women and a man, in the other two men and a woman, gardaí said last night.
Five of the injured were taken to Portlaoise and one to Tullamore Hospital. Two of the injured were believed to be serious, gardaí said.
The road remained closed last night and diversions were in place. Garda Forensic Collision Investigators were at the scene.
Witnesses are asked to contact the Gardai at Roscrea on 0504 24230 or the Garda Confidential Line on 1800 666 111.