The plane was diverted for five hours while the pipes were unclogged.

An international flight was delayed five hours when the pilot had to make an emergency landing after the aircraft toilets became blocked.

The lavatory system became clogged with "something solid" during the flight from Toronto to Pakistan on Saturday, the Manchester Evening News reported.

It was decided that the Pakistan International Airlines flight would divert to Manchester for the "convenience of passengers".

Wikicommons The Pakistan International Airlines flight was over the North Sea when the blockage was discovered.

"Toronto-Lahore flight PK-798 has been diverted to Manchester as its toilets got choked, due to something solid thrown in by passengers," airline spokesman Danyal Gilani said.

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"Keeping in view the convenience of passengers, the flight has been diverted to Manchester where the toilets will be serviced before the flight continues its onward journey," he said in a Twitter post.

"Inconvenience caused to passengers is regretted."

A Boeing 777 generally has eight or nine toilets which are connected by one drain line.

The plane was diverted for five hours while the pipes were unclogged, it was reported.

It's not the first time toilet trouble caused a flight to make an emergency landing. In March 2015 a British Airways flight was forced to return to London's Heathrow airport after a "smelly poo" was discovered in one of the toilets.

The flight was 30 minutes into the journey to Dubai when the pilot made the decision to turn back for health and safety reasons.