United States Homeland Security Secretary, Ms. Janet Napolitano, has called for more international cooperation in protecting transport routes against attack and controlling trade in potentially dangerous materials.

In a speech in Brussels, Napolitano said security and customs authorities needed to work closer with industry to develop new technologies and share information to track chemicals that can be used to produce weapons, Reuters reported on Friday.

Not enough effort is made to minimise potential disruptions to trade and transport in case major infrastructure hubs are damaged by attacks.

“Consider the consequences of such an attack… Beyond the immediate impact… the consequences could quickly snowball and impact economies around the world.”

“People across the world would find empty store shelves and serious shortages in needed medical supplies,” she added.

Governments across the world have been reviewing aviation and transport security since US-bound parcel bombs sent by air from Yemen were intercepted in Dubai and Britain last October.

In the EU, the bloc‘s 27 governments are preparing a plan on how to screen cargo from third countries, although a German proposal for a “blacklist” of airports with insufficient security standards for cargo has been rejected.

But calls from more screening of shipments have led to clashes with industry in the US and Europe as transport companies grew concerned over the cost of tighter security, particularly of sophisticated imaging technology designed to detect explosives.

Addressing such concerns, Napolitano said while new technologies would be used, intelligence-gathering and new standards were also an important tool. The US would also send “hundreds” of aviation and customs officials to help protect transport hubs.

She said joint efforts by customs authorities from the US and other countries had helped investigate smuggling of chemicals that could be used to make explosives into Afghanistan and Pakistan in the last year.