A footbridge providing the main access point to the AL_A-designed Museum of Art, Architecture and Technology in Lisbon has been closed over fears of collapse, after 15,000 visitors turned out for the opening of the museum.

The bridge has been closed all day and its entrances guarded by police, after unexpected visitor numbers raised fears that the bridge might break.

The structure links the Belém district's main train station with the MAAT museum, which sits on the edge of the Tagus River.

The sinuous, tile-covered museum opened to the public on 5 October 2016, coinciding with the beginning of the Lisbon Architecture Triennale.

Thousands of visitors were lured to the waterfront by the dramatic swooping roof of the museum, which was designed by British firm AL_A, founded by Amanda Levete.

Crowds backed up across the footbridge – which spans eight lanes of traffic and two railway tracks – and queues formed along both platforms of Belém station.

Today, the bridge was visited by an engineer and closed indefinitely over fears that it could not support the weight of museum visitors.

The bridge is one of the few crossing points for an eight-lane road, and also connects the station and waterfront with the Paulo Mendes da Rocha-designed National Coach Museum.

While the bridge remains closed, visitors will be forced to walk 1 kilometre in either direction to other crossings.

The official opening of the MAAT marks the end of the first phase of construction. Phase two, expected to launch in March 2017, will see the addition of a new footbridge spanning the motorway.