Greece imposed a ban on all international mail on Wednesday following a series of parcel bombs addressed to foreign targets, as police hunted a gang of left-wing militants believed to be behind the campaign.
While authorities came under fire for failing to contain the plot, police appealed for information leading to the capture of five men suspected of trying to attack embassies in Athens and the offices of several European leaders.
One of the parcels was addressed to French President Nicolas Sarkozy, while others were intended for German Chancellor Angela Merkel and Italian Prime Minister Silvio Berlusconi.
The wanted men are all aged between 21 and 30.
The two-day ban on mail and parcel dispatches abroad, which was announced late Tuesday, is intended to give authorities more screening time.
"The transport of mail and parcels abroad will be halted for 48 hours to enable follow-up inspections," the police department said in a statement.
Police managed to track down most of the 13 parcels accounted for since the plot surfaced on Monday but not before one made its way to the German chancellery mail room in Berlin, where it was neutralised by Merkel's staff.
The parcel intended for Berlusconi was found on a courier plane bound for Paris that was rerouted to Bologna late on Tuesday night.
The bombs are contained in hollowed-out books and are believed to contain a small amount of explosives, according to police.
Two men aged 22 and 24 have already been arrested since Monday when two of the parcels were found among their belongings, one of them addressed to Sarkozy.
Both were armed with handguns and one was wearing a bulletproof vest.
But early relief at the arrests was followed by another wave of parcel bomb sightings on Tuesday. Two burst into flames whilst handled by staff at the Swiss and Russian embassies without injuring anyone.
Media commentators pulled no punches on Wednesday in criticising the police for failing to contain the campaign that put the spotlight on Greece again, following an ongoing furore in Europe over the country's parlous finances.
"The new terrorists and those guiding them seek to create negative impressions of Greece abroad," wrote top-selling Ta Nea daily, which nominally supports the Socialist government.
"They are also trying to cause a stir in foreign media...and foment fear among public opinion," it added.
"The country faces a serious terrorism problem as is evident from the actions of a new generation of extremists," added liberal Kathimerini daily.
The two suspects are refusing to identify themselves or cooperate with the authorities, according to police.
Police have linked one of them to Conspiracy of Fire Nuclei, a far-left group that appeared in 2008 and until now had limited its activities to arson and minor bomb hits against government buildings and the offices and homes of politicians.