A woman in her 40s and a teenage girl have been arrested by Gardai investigating a serious assault in Co Tipperary on Saturday.
A woman in her 20s is in a critical condition in hospital.
An Garda Siochana said the two people arrested were detained under Section 50 of the Criminal Justice Act 2007 at Garda stations in Co Tipperary.
They said the alleged assault happened on the R494 at Birdhill and appealed for witnesses.
They want to speak to drivers who were on the R494 between Birdhill and the M7 motorway between 5pm and 6pm on Saturday and may have dash-cam footage.
In particular, they want to trace the movements of a grey 162 Ford Transit van and a blue 161 Volkswagen Touran people carrier.
They said they were travelling in convoy or driving dangerously between 4.30pm and 5.30pm on Saturday around Birdhill village, the townlands of Cooleen, Crag Cross, Shower Cross, Kylebeg, Annaholty and Thornhill.
Gardai said they were aware footage of the incident was circulating online and have asked people not to share it on social media or on messaging apps, but instead to provide it to investigating gardai.
Subscribe or register today to discover more from DonegalLive.ie
Buy the e-paper of the Donegal Democrat, Donegal People's Press, Donegal Post and Inish Times here for instant access to Donegal's premier news titles.
Keep up with the latest news from Donegal with our daily newsletter featuring the most important stories of the day delivered to your inbox every evening at 5pm.