Former Ukrainian politician Andriy Portnov, who worked as a senior aide to pro-Russian former President Viktor Yanukovych, has been shot dead just outside the Spanish capital Madrid, a Spanish national police source told CNN.

Unidentified gunmen shot dead a former Ukrainian politician on Wednesday outside a school in a wealthy suburb of Madrid, Spain's Interior Ministry said.Andriy Portnov, 51, was previously a senior aide to a pro-Russian former Ukrainian president,

The man, named by Ukrainian and Spanish sources as Andriy Portnov, had just dropped his children off at the school, reports say.