The Panama Canal was closed to ships for the first time in over two decades Wednesday after heavy rains swelled nearby lakes flowing into the key transport route that handles five percent of global trade, officials said.

The Panama Canal Authority (ACP) said downpours had filled the Gatun and Alhajuela lakes to historic levels, forcing it to ''temporarily'' suspend traffic.

Senior ACP official Manuel Benitez said the canal was closed in order to open flood gates to relieve one of the lakes. The authority was ''taking steps to normalize transit operations in the next few hours,'' he added.

A canal authority official told AFP it was the first time transit through the canal had been suspended since the US invasion of Panama in 1989.

Passage through sections of the canal have been temporarily blocked on other occasions as a result of accidents, but not operations along the entire length of the canal as was the case Wednesday.

Each year, around five percent of all international trade passes through the 80-kilometer (50-mile) man-made artery linking the Atlantic to the Pacific, with around 40 ships passing through the canal each day.

At least eight people have died in Panama - including two girls who drowned in a river - as a result of the heaviest rains in the 73 years records have been kept, President Ricardo Martinelli said.

At least 1,500 people have been left homeless and were being offered access to temporary shelters.

Floods have collapsed bridges, destroyed homes, flooded a cemetery and caused disruptions to electrical and water supply.