An explosive device that was placed outside offices in the southern Athens neighborhood of Kallithea on Saturday but failed to detonate is likely to have been the work of the terrorist group Revolutionary Struggle, which has been particularly active in the city over the last few months. Sources told Kathimerini that initial tests suggest that the device contained ANFO, a mixture of ammonium nitrate and fuel oil that is a common explosive used in mining and quarrying. A massive bomb that went off outside Citibank’s headquarters in Kifissia in February, and which was also claimed by Revolutionary Struggle, was found to contain ANFO too. Police said that Saturday’s bomb was placed outside the entrance to a building that houses offices for Alpha Bank, a shipping company and, until recently, served as the headquarters of a French company. A recorded telephone warning was made to the Eleftherotypia newspaper.