Image copyright Science Photo Library Image caption The Suez Canal is one of 14 "chokepoints"

The world's food security is increasingly reliant on 14 "chokepoints" for trade, a think-tank report has warned.

UK-based Chatham House says more needs to be done to protect key transport routes such as the Panama Canal, the Suez Canal and the Turkish Straits.

Almost 25% of the world's food is traded on international markets.

This, the report says, makes food supply and prices vulnerable to unforeseen crises or climate change.

Infrastructure at the chokepoints is often old and would struggle to cope with natural disasters which are expected to grow in frequency as the planet warms, the report authors add.

They urge governments to invest in "climate-resilient" infrastructure, and diversify food production and stocks.

The report gives examples of how reliant the world is on this trade:

Three-quarters of Japan's maize and wheat imports pass through the Panama Canal , which is just 300m (984ft) wide

, which is just 300m (984ft) wide Just over a third of grain imports for the Middle East and North Africa pass through the Turkish Straits , with no alternative maritime route available

, with no alternative maritime route available More than 25% of soybean exports are shipped across the Straits of Malacca

Roads in Brazil , the world's largest exporter of soybean, are at risk of flooding and landslides because of heavy rains

, the world's largest exporter of soybean, are at risk of flooding and landslides because of heavy rains US Gulf Coast ports face storm surges boosted by rising seas

face storm surges boosted by rising seas Gulf Co-operation Council countries rely on grain from the Black Sea region that is transported via the chokepoints of the Russian and Ukrainian railways/ports, the Turkish Straits and the Suez Canal.

"The risks are growing as we all trade more with each other and as climate change takes hold," says Laura Wellesley, one of the study's authors.

There are risks for both the food security of importing countries and the economies of those exporting food, she added.