Belgium Interior Minister Jan Jambon | Emmanuel Dunand/AFP via Getty Images Belgian police to secretly film terror suspects Interior minister says devices will monitor returned foreign fighters.

Belgian police will soon be allowed to secretly film terror suspects regardless of whether they have been charged by a court, Belgium's Interior Minister Jan Jambon said Wednesday.

"We will use cameras to secretly film people who have been named in terror investigations," Jambon told Belgian broadcaster Radio 1, adding that the measure, approved Wednesday by the federal cabinet, will come into force by the end of 2016.

The surveillance could include cameras installed outside suspects' homes, and "bodycams" attached to officers' bodies that record what's happening in front of them, Belgian media reported.

Jambon said this would make it easier to monitor terror suspects that have returned from Syria.

Of an estimated 4,000 EU citizens who traveled to Syria and Iraq to join terror organization Islamic State in 2015, around 30 percent have returned to their home country, according to a report published earlier this year. It suggested that Belgium has the highest number of foreign fighters per capita.