Greek police foiled four attempted parcel bomb attacks Monday, allegedly targeting French President Nicolas Sarkozy and three embassies in Athens, after one of the devices exploded at a delivery service, leaving a worker hospitalized with burns.

Motorcycle police later arrested two Greek men, aged 22 and 24, several hundred meters (yards) from the blast site in central Athens. Police said the men were carrying handguns and bullets in waist pouches, and one of them wore a bulletproof vest, a wig and a baseball cap.

Parts of the city centre were cordoned off for more than an hour around midday as three the three unexploded bombs, found at a different delivery service and in the suspects’ backpacks were defused in a series of controlled explosions.

Beyond Sarkozy, the targets were the Athens embassies of Mexico, The Netherlands and Belgium, police said. The return address labels included the names of a senior government official, a Greek charity, and a well-known Greek criminologist, police said.

They said the one that exploded was addressed to the Mexican embassy. The one addressed to the Dutch embassy was found and defused at a delivery service, police said. The other two - the one addressed to the Belgian embassy and the one addressed to Sarkozy - were found on the suspects, police said.

Police were searching other courier services and post offices to check whether other parcel bombs had been sent.

Sarkozy’s office had no comment on the attempted attacks.

They occurred amid an international security alert over two powerful bombs shipped last week from Yemen to the United States.

Police said both suspects arrested Monday were Greek, and one was suspected of belonging to Conspiracy Nuclei of Fire, a domestic anarchist group that has carried out dozens of crude bomb and arson attacks.

Attacks by Greek militant groups - ranging from deadly attacks against police and powerful bomb blasts to minor arson attacks - have flared since massive riots occurred across the country in December, 2008, triggered by the police shooting of a teenager.

Embassies and overseas-based companies have been targeted in past attacks, often in solidarity with protests occurring abroad, such as the demonstrations in France protesting the raising of the retirement age.

In June 2009, a senior official at the country’s public order ministry was killed by a letter bomb - an attack also linked to Greek militants.

After the official’s death, officials said screening of mail would be more intense but the procedures remain mostly unchanged.

Parcels sent by private courier are sealed in front of a company employee and the sender, and they are only X-rayed if they pass through an airport.

The suspects have not yet been charged.