Over 2,000 swimmers from 50 countries raced from Asia to Europe in the annual Bosphorus Cross-continental Swimming Race on Sunday.

They thrashed across the Bosphorus, the Istanbul seaway which marks the traditional boundary between the two continents, about 700 metres at its narrowest point. 

The race began on the Asian side of Istanbul at the harbour of the Kanlica borough, as swimmers took to the water and headed for Europe.

The 30 kilometre strait, bridged for the first time in 1973, is one of the world's most spectacular and hotly contested waterways.