A fourth teenager has been arrested in connection with the disorder at Runshaw College.
On Monday (4 March) a gang of 12 people arrived at the college site in Leyland for a pre-arranged fight.
Lancashire Police say during Thursday (7 March) morning they arrested a 17-year-old boy from Preston on suspicion of a public order offence.
He has been bailed pending further enquiries with strict bail conditions until April 4.
The pre-arranged fight happened around 4pm when cars including a Volkswagen Polo, Vauxhall Astra and a Nissan Micra pulled up and those inside towards the Worden Park side of the college campus.
They shouted and confronted students, brandishing a machete, crowd bar and knives.
A 17-year-old boy was taken to Chorley Hospital after being cut on the arm.
Two men aged 18, both from Preston, an 18-year-old man from Kirkham and three 17-year-old boys from Preston were arrested on suspicion of public order offences. All have been bailed with strict conditions to April 2.
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Anyone with information or video footage is asked to contact 101 quoting reference 933 of March 4 and the footage can be uploaded via the Police website, selecting ‘Report a Crime or incident’.