A 16-year-old Syrian refugee went on trial in Germany Monday accused of planning a bomb attack on behalf of the Islamic State jihadist group. 

The youngster was arrested at an asylum shelter in the western city of Cologne in September, with the authorities describing him as a "serious threat." 

Police at the time said the suspect's mobile phone showed he had been in touch with an IS contact abroad and had expressed willingness to carry out an attack. 

Investigators found online chat messages on the phone that included "concrete instructions" for building an explosive device, prosecutors added. 

Officers searching his accommodation discovered a battery pack, 70 sewing needles and several butane gas cartridges -- items that could be used to prepare a bomb, DPA national news agency reported, citing the charge sheet. 

The trial at the district court in Cologne, scheduled to last until March 20, is being held behind closed doors because the accused is a legal minor. 

A court spokesman said he had to answer charges of planning "a serious act of violence threatening state security." 

If convicted, he faces a maximum sentence of five years' detention under the juvenile penal code.--AFP

Source :NNA