London, Jan 28 : Freight travelling through the Suez Canal has almost halved since Yemen's Houthi rebels began attacking cargo ships in the Red Sea, Sky News reported.

The key shipping lane links producers in the Asia-Pacific region and Western markets -- and longer, alternative routes have caused delays and increased costs.

UNCTAD (United Nations Conference on Trade and Development), which supports developing countries in global trade, said the number of ships using the canal over the last two months had fallen by 39 per cent, leading to a 45 per cent decline in freight tonnage, Sky News reported.

Jan Hoffmann, the agency's head of trade logistics, said there were now three key global trade routes disrupted, following Russia's invasion of Ukraine and the Panama Canal, where low water levels from drought meant shipping last month was down 36 per cent year-on-year and 62 per cent from two years ago, Sky News reported.

He said: "We are very concerned. We are seeing delays, higher costs, higher greenhouse gas emissions."

Pollution was rising, he said, because ships were opting for longer routes and also travelling faster to compensate for detours.

The Suez Canal handles 12-15 per cent of global trade and 25-30 per cent of container traffic.

Container shipments through the canal were down 82 per cent in the week to 19 January from early December, Sky News reported.

Hoffmann said food prices could feel the impact, adding about half of the increases seen since the war in Ukraine were due to higher transport costs, although consumers in developed countries may take some time to see an effect.

/IANS