Teachers at some sixth-form colleges in Sussex have walked out amid a pay dispute with the government.
Some 8,000 students at Brighton, Hove and Sussex Sixth Form College (BHASVIC), Varndean College and Collyer's in Horsham are being affected by three consecutive days of strike action that started on Tuesday.
The National Education Union said it was taking action after the government failed to resolve a "clear pay discrepancy" between non-academy sixth-form colleges and their academy counterparts.
A Department for Education spokesperson said: "Sixth form colleges are responsible for the setting of appropriate pay for their workforce and for managing their own industrial relations."