Spain's main train drivers union on Wednesday announced four days of strikes in September to protest a breakdown in talks with state train operator Renfe over collective agreements on staffing and work conditions.

The SEMAF union said the 24-hour strikes, which would affect both passenger and freight trains, would be staged on September 4, 11, 14 and 15.

The union, which has roughly 5,000 members, announced last week that its talks with the company had ended without agreement.

Government-imposed minimum services on key routes means the strike is not likely to severely disrupt travel.