A Greek Left-wing activist was arrested on Monday for an arsonist attack at a gold mine in northern Greece which caused damages and slight injury of two guards, police authorities announced.

The 54-year-old mechanic, who is a member of the main opposition Radical Left SYRIZA party, is accused of instigating the attack involving 30 people on the premises of the gold mine at the Skouries area on Sunday.

The assailants torched down vehicles and doused two guards with flammable liquids. The suspect, who was released within a few hours, claims he was being prosecuted with political motives. According to local media, he threatened eye witnesses with lawsuits for defamation.

"We will safeguard law and order and foreign investments in our country," Greek Public Order Minister Nikos Dendias said Monday during a visit at Skouries.

The gold mine is controlled by a wide majority of some 95 percent from the Canadian firm Eldorado Gold.

Condemning the attack, representatives of the firm told Greek media that their one-billion-euro investment creates thousands of job positions in Greece at a period when the debt-ridden country struggles to exit an acute economic crisis and Greeks suffer from 27 percent unemployment.

However, the project has been met with strong reactions in recent months from locals who protest against environmental destruction.