Portugal's FC Porto announced on Tuesday that they had signed defender Bruno Martins Indi from Feyenoord for the next four seasons.

The club bought the 22-year-old Dutch central defender for 7.7 million euros until 2018.

The Portugal-born player, whose parents are from Guinea, has been at Feyenoord since 2009 and had a contract until 2016.

Porto finished third in last season's Portuguese league despite previously having won for three consecutive years.