ATHENS — Attackers targeted the Microsoft main office in the Greek capital in a pre-dawn arson attack Wednesday, smashing the entrance with a mini-van and blowing up gas canisters, police said. Anti-terrorist police were investigating, and authorities did not rule out an extremist group was behind the attack, which caused no casualties. Two or three masked men immobilised two security guards around 3:45AM local time, then rammed the stolen mini-van through the entrance, and set fire to the van, which was packed with gas canisters, police said. The fire and explosion damaged the entrance and ground floor of the building, the Greece corporate headquarters of the US technology giant, located in the northern Athens suburb of Maroussi. Attacks against targets such as diplomatic missions, state offices, companies and banks, which usually do not cause casualties, are frequent in Greece and blamed by police on extremist and anarchist groups. — AFP