ATHENS, Jan. 20 (Xinhua) -- An explosive device went off on Sunday noon at a major shopping mall in the northern suburb of Athens, causing slight injury of two security guards, local authorities announced.
The small power bomb had been placed on the building's first floor near a bank branch, according to police sources. The two guards have been transferred for first aid to a nearby hospital with minor injuries from shattered glass.
Shortly before the explosion, there had been two warning phone calls at a Greek daily and news portal to evacuate the building. According to yet unconfirmed reports the perpetrators misled police, indicating that the device had been hidden at the garage.
As a counter-terrorism squad is searching for clues, checking the security cameras, police has cordoned off the area which is usually flocked with thousands people during weekdays and Saturdays.
On Sundays, only cafeterias, restaurants and cinemas are open at the popular shopping center. It is estimated that there had been approximately 200 people, including several children, inside the building before the explosion.
No group has claimed so far responsibility for the attack which falls into the high risk category, according to police experts speaking anonymously to media.
Sunday's terrorist attack follows a string of attacks at the conservative New Democracy party headquarters, journalists' homes and the house of government spokesman's brother over the past ten days.
Two anarchist groups have claimed responsibility for the first round of attacks with devices made up with gas canisters on January 10 outside five journalists' homes "in protest of the coverage of the debt crisis which has hit Greece."
In the early hours of Monday, perpetrators opened fire with Kalashnikov rifles at New Democracy's headquarters with one of the bullets reaching the office of Prime Minister Antonis Samaras.
Sunday's blast drew strong reactions of all political parties which condemned it as an effort to destabilize democracy, as local political analysts talked about an alarming escalation of political violence.
"The terrorists' real target is democracy, social peace and the prospect for the nations' economic recovery...Democracy cannot be terrorized," said a statement issued by Citizen's Protection Ministry in charge of public order.
Greek opposition parties issued similar statements, condemning the terrorist attack.
Greece has suffered from domestic terrorism over the past four decades and after the outbreak of the debt crisis in 2009 which has led the country to the brink of bankruptcy, dramatically eroding living standards.Several groups have linked attacks with harsh austerity measures implemented to resolve the crisis.