Petros Giannakouris/Associated Press
ATHENS — Unidentified gunmen sprayed bullets into the headquarters of Greece’s governing New Democracy party in central Athens before dawn on Monday, adding to a wave of politically motivated violence in recent days as Greece struggles with its worst economic crisis in a decade.
No one was injured in the attack, in which one bullet entered the office of Prime Minister Antonis Samaras.
Though there was no public claim of responsibility for the shooting, the episode followed a spate of attacks on other symbols of the Greek establishment that are believed to have been carried out by far-left militant groups. Those attacks over the last week involved canister bombs detonated at government offices, banks and the homes of five prominent journalists in Athens.
A government spokesman warned on Monday of a “dangerous escalation of spreading terror.”
Taken together, the episodes point to a rise in violent militancy on the far left in Greece, after a similar rise on the far right, where the neofascist group Golden Dawn has carried out a series of attacks against immigrants.
Mr. Samaras’s fragile coalition government has been rocked recently by accusations that it has failed to pursue rampant tax evasion by the wealthy and well-connected. The publication of a list of more than 2,000 Greeks with bank accounts in Switzerland, which the government was given but did little to investigate, has touched off a scandal and galvanized public opinion in recent weeks.
The opposition Syriza party, which until recently was ahead of Mr. Samaras’s bloc in opinion polls, has sought to capitalize by mounting parliamentary investigations into the matter. The party’s lead shrank when Mr. Samaras secured a payment of almost $ 47 billion from its international lenders last month, part of a bailout plan that Syriza has said it would try to scuttle if it wins power.
Mr. Samaras, for his part, has pointed to outbreaks of violence — first by Golden Dawn and now by anarchist and left-wing groups — as warnings of what could happen to the country if he were not in charge. “Democracy will not be terrorized,” he said on Monday.
All of Greece’s opposition parties, including Syriza, Independent Greeks, Golden Dawn and the Communist Party condemned the shooting attack on Monday.
Urban political violence has tended to flare in Greece at moments of political chaos and economic deterioration. A group called November 17 mounted terror attacks against politicians and businessmen for decades after the fall of the country’s military junta in 1974; the police finally eradicated that group in 2002, but others have sprung up since then, including anarchist groups that have sowed chaos by attacking the police and throwing Molotov cocktails during anti-austerity demonstrations.
The latest wave of violence began after dozens of suspected anarchists were arrested last week in a raid at the Villa Amalia, a longtime gathering point in central Athens for far-left groups and students. Petrol bombs were confiscated in the raid.
Security guards at Mr. Samaras’s party offices saw two men get out of a car shortly before 3 a.m. Monday and open fire according to the police. The offices were empty at the time.
State television reported on Monday that antiterrorism officers had joined the investigation, but the police did not publicly speculate about who might have been responsible for the shooting.
A string of attacks involving homemade gas canister bombs on Friday that targeted five prominent journalists was claimed by an anarchist group called Militant Minority-Lovers of Lawlessness. It cited Greek media coverage that it saw as sympathetic to the austerity drive imposed by the government and its international creditors, the European Union and the International Monetary Fund.
This article has been revised to reflect the following correction:
Correction: January 14, 2013
An earlier version of this article misstated a group that claimed responsibility for attacks involving homemade gas canister bombs on Friday. The group was Militant Minority-Lovers of Lawlessness, not Military Minority-Lovers of Lawlessness.