Greek officials on Thursday promised "swift and exemplary" punishment for three strawberry plantation foremen who allegedly shot and injured 29 Bangladeshi laborers protesting pay arrears in the country's rural south.

Police are seeking the three suspects who disappeared after Wednesday's shootings, which occurred during a confrontation with some 200 Bangladeshi farm workers who say they have not been paid for half a year.

Seven Bangladeshi workers were still receiving treatment in local hospitals, but none have life-threatening injuries.

Government spokesman Simos Kedikoglou condemned the "inhuman, unprecedented and shameful" shootings near the village of Manolada in the southern Peloponnese region.

The plastic-topped greenhouses that smother Manolada's broad plains account for most of Greece's strawberry output, using cheap labor by Asian immigrants often housed in primitive conditions. Several attacks on migrant strawberry workers there have been recorded in recent years, but Wednesday's was the worst so far.

"The barbarous attack ... conjures up images of a slavery-based South that have no place in our country," Justice Minister Antonis Roupakiotis said.

Political parties and trade unions expressed shock, and about 100 people took part in a protest by labor groups outside the Labor Ministry in Athens.

"Before the shootings, there was an altercation between the foreign workers and the three foremen over six months' outstanding wages," police spokesman Christos Parthenis said. "After that the three fugitives left the spot, and returned shortly later holding two shotguns and a handgun, and opened fire on the crowd."

Police found five used shotgun cartridges were found on the spot.

Authorities have arrested the owner of the farm, which is about 260 kilometers (160 miles) southwest of Athens. On Thursday, they also arrested a local man on suspicion of hiding the three fugitives.

Greece is caught in its worst financial crisis in decades, and is surviving on international rescue loans granted in exchange for harsh austerity measures. It is in the sixth year of a deep recession, with unemployment at a record 27 percent.

The economic pain, coupled with waves of illegal immigration in recent years, has fuelled a rise in anti-immigrant sentiment that swept members of an extreme far-right party into Parliament last year.

Golden Dawn, which holds 18 of the house's 300 seats, is currently polling third in opinion surveys, at about 10 percent. The party denies accusations from most mainstream opponents that it is neo-Nazi, although its website brims with Nazi literature and references.

The party issued a statement Thursday condemning the Manolada shootings. It then added: "We also condemn those who illegally employ illegal immigrants, taking the bread away from thousands of Greek families."

"All illegal immigrants must be immediately deported," it said.

The labor minister ordered an urgent inspection of work conditions at the Manolada strawberry farms.

The country's main labor union, GSEE, described conditions at Manolada as a modern form of slavery.

"The criminal act in Manolada ... shows the tragic results of labor exploitation, combined with a lack of control" by the government labor inspectorate, a union statement said. "In Manolada, and particularly in the strawberry plantations, a sort of state within a state has been created."