World number one Novak Djokovic has pulled out of the Serbia Open tennis following the death of his grandfather during the Monte Carlo Masters event last week, the Serbian said on Wednesday.

The world number one said he had "no emotional energy left" after being thrashed by Rafael Nadal in the Monte Carlo final on Sunday, and would be back in action at the Madrid Masters, which starts on May 6.

The April 30-May 6 Serbia Open is organized by Djokovic's uncle Goran.

(Writing by Gregory Blachier; Editing by Clare Fallon)