“I was made aware of the incident this morning and have spoken to West Lothian Council, the Justice Secretary and the Education Secretary.
“Our thoughts are with the student affected, who is being treated at St Johns hospital in Livingston. This is a serious but thankfully extremely rare incident. 
“West Lothian Council and the police are working with the school and those involved and I will be seeking a meeting with them as a matter of urgency.
“West Lothian Council is signed up to the Scottish Government’s ‘No knives better lives’ campaign and this has been delivered across all West Lothian schools. However it is important that we understand the details of this incident, learn the lessons and continue to work with schools and pupils to reinforce the dangers of carrying a knife.”
A West Lothian Council spokesperson said: “A police investigation is currently ongoing into an incident at St Kentigern’s Academy in Blackburn where one pupil sustained a serious facial injury. West Lothian Council makes the safety of the pupils in our care our top priority. We have been working with Police Scotland on a number of initiatives to promote pupil safety in our schools recently, including delivering the No Knives, Better Lives campaign to educate young people on the consequences of knife crime.
“It is not appropriate to say more while the police investigation is ongoing.”
A Police Scotland spokesperson said: “Police in West Lothian were called to St Kentigern’s Academy in Blackburn around 8.55am on Friday 15 September after a 14-year-old boy sustained a serious facial injury. He has been taken to St John’s Hospital for treatment and a teenage boy is currently detained by officers in connection with this. Enquiries into this incident are ongoing.”