FIRES broke out at DHL warehouses in the UK and Germany over the summer and Russians are suspected, reports Reuters.

The Kremlin is suspected of ramping up hybrid attacks on Europe in recent months. The air freight industry is braced for further action.

Suspected Russian sabotage activities targeting the air freight industry have been on the rise this year, and the industry is preparing for further action.

Brandon Fried, the executive director of the Airforwarders Association, which represents US air cargo companies, told Business Insider that the industry had been on high alert since 9/11.

"So regardless of who is perpetrating this, whether it's another country or whether it's a terrorist organisation, our industry has been vigilant for quite some time," he said, referencing two fires at DHL warehouses earlier this year that have been linked to Russia.

"They want to cause fear and panic, but we, as a community, are not going to let them. One of our overriding messages is that we're vigilant," Mr Fried said.

Western officials have said the fires, which took place at two DHL sites in the UK and Germany in July, may have been part of Russian sabotage operations that ultimately aimed to target North America, The Wall Street Journal reported earlier this week.

One package caught fire before being loaded onto a plane at a DHL freight centre in Leipzig, eastern Germany, while a similar incident took place at a DHL warehouse in Birmingham in the UK.

Thomas Haldenwang, the president of Germany's domestic intelligence agency, did not blame Moscow.