Shortly before 6.00pm 2.4metres of railing on the Pont des Arts, which joins the Louvre museum to the left bank of the river Seine, collapsed, causing no injuries but enflaming a debate as to whether the thousands of padlocks that cover the length of the bridge should be removed
An architect and local officials rushed to the scene and a barrier was put up to stop people going on to the bridge.
Police promised to reopen it on Monday morning.
Since 2008 lovers have been attaching padlocks to the Pont des Arts in a craze that has become so popular that the full 150-metres length is covered and the practise it has spread to other bridges in the French capital.
Forty locks were recently removed from the Eiffel Tower and many have previousy been taken of the Pont des Arts, only to be replaced.
Two young Americans living in Paris have collected thousands of signatures on a petition launched in March calling for the padlocks to be removed on the grounds that they damage the bridges and are an eyesore.
Local officials have raised concerns that parts of the bridge could fall on boats passing underneath it.
Love locks are believed to have appeared first in the Serbian town of Vrnjacka Banja in the early 20th century and have since spread to many parts of the world, taking off, especially in Italy, in the 2000s.
Background: Paris bridge weighed down by love