An unidentified number of suspicious packages due to be sent abroad was discovered at Athens International Airport "Eleytherios Venizelos" on Tuesday evening, as Greece is gripped since Monday in a thriller of minor explosions of parcel bombs delivered to foreign embassies.

According to Greek media, local counter-terrorism experts have rushed to the airport to examine the packages, as Greek authorities have signaled red alert for terrorism.

Nine parcel bomb incidents have been confirmed so far by police in Athens, including one outside the Greek parliament on Tuesday noon.

Furthermore, according to the latest information from Athens, the booby-trapped letter which was found on Tuesday afternoon at the office of German Chancellor Angela Merkel, was supposed to have been sent by the Greek Finance Ministry.

The bomb device traced in this parcel is said to be similar to the ones used in attacks in embassies in Athens.

One of the parcel bombs detonated in the Greek capital on Monday was due to be sent to the office of French President Nicolas Sarkozy. According to Greek media reports the name of Greek Deputy Prime Minister Theodoros Pangalos was written on that parcel as sender. One woman employee of a courier company was injured on Monday noon in the first explosion of a booby- trapped letter that alarmed Greek officials and foreign diplomats.

No group has claimed responsibility for the series of attacks, but local counter terrorism experts and political analysts suspect domestic guerrilla groups which have operated for years in the country, even thought this is a new model of operation for them.

In an e-mail official announcement on Tuesday afternoon Greek police confirmed the discovery of five bomb devices all over Athens on Tuesday.

The recipient of the booby-trapped parcel which was detonated outside the parliament was the Chilean embassy in Athens.

The courier found it suspicious and on his way to the embassy notified experienced guards at the government's headquarters and then left it to the hands of experts at the nearby parliament building who detonated it.

Also on Tuesday two bomb devices went off at the garden of the Swiss embassy and the Russian embassy in Athens. In both cases employees spotted the suspicious packages and the parcels exploded before counter terrorism squads arrive.

Greek experts detonated during the same day two booby- trapped parcels outside the Bulgarian embassy and inside a courier company with the German embassy in Athens as the recipient, Greek police officials said.

Suspicious packages examined by police at the Panama's embassy at Piraeus, the political office of Greek former Prime Minister Costas Simitis, the home of a Greek district attorney who deals with terrorism cases and an Air Force base in Eleysina, close to Athens, contained no bomb devices.

Greek authorities have notified foreign embassies in Greece to be on alert since Monday, when a bomb package with Mexican embassy as the recipient blew up in the hands of a courier company employee, leading to the arrest of two suspects.

A district attorney on Tuesday afternoon formally accused 22- year-old Panagiotis Argyros and 24-year old Gerasimos Tsakalos of terrorism activity.

The younger detainee has been wanted by police since 2009, as suspect of membership in the local guerrilla group "Conspiracy of the Nuclei of Fire", which has acclaimed a series of terrorist attacks in recent years against political, police and financial targets.

Greek authorities also released again on Tuesday afternoon the names and photographs of five youths wanted since last year for membership in the same guerrilla group.

In June this year a police officer was killed when a booby- trapped package bomb exploded inside the Ministry of Citizens' Protection, next to the office of the then Minister Michalis Chrissohoidis. Greek terrorism groups operate in Greece since the end of a military dictatorship in 1974. Dozens of people were killed in hundreds of attacks attributed to "November 17" until the group was dissolved by police before the 2004 Athens Olympic Games.

Ever since less dangerous groups had made attacks on various targets, such as the U.S embassy in Athens in 2007. Guerrilla groups have stepped up attacks after the deadly injury of a teenager by Greek police in December 2008. Three people have died ever since in terrorism attacks.

Despite the arrests of key members of guerrilla groups this spring, terrorists have threatened with more attacks due to the austerity measures implemented by the government to tackle an acute economic crisis.