A man was seriously injured in the attack yesterday.
Gardaí have made a second arrest in relation to a stabbing in Longford Town yesterday.
A man in his 20s was seriously injured in the attack outside a fast food restaurant on Main Street at 3.15 yesterday afternoon.
He was taken to Mullingar Regional Hospital for treatment of his injuries.
Gardaí have since arrested a woman, aged in her 20s, who's being detained in Roscommon Garda Station.
A man, also in his 20s, who was arrested earlier, remains in custody in Granard Garda Station.
They're being detained under section 4 of the Criminal Justice Act, 1984.