Belgium inaugurated the world's biggest lock at the port of Antwerp in the presence of Belgium's King Philippe.

The new lock was under construction for almost five years and took up to a week to fill with water.

The port's economic activity will rely heavily on the ability of large cargo ships to reach the docks behind the lock.

During the opening ceremony, King Philippe and other officials pressed buttons to open the lock for the first time.

A 34,000 tonne container ship, the Grande Lagos, made its way out of the port through the lock.

The new structure is 500 metres long, 68 metres wide and 18 metres deep, allowing container vessels to fit easily.

Antwerp is Europe's second busiest port, handling millions of tonnes of cargo annually.