At least 20 migrant strawberry pickers were shot and wounded in southern Greece, in a pay dispute after a foreman opened fire on them with a shotgun, police have said.

Wednesday's incident occurred near the village of Manolada, about 260 kilometres west of Athens.

Haralambos Sfetsos, the police captain, said most of the wounded workers were from Bangladesh.

"The injured have been taken to various nearby hospitals. We have been informed that none of the injuries are life-threatening," Sfetsos told AP news agency.

"We have identified the three foremen and are looking for them. They are three Greek men, who live locally."

He said the shooting occurred when about 200 workers at the strawberry field demanded six months unpaid wages and "moved threateningly" toward three foremen, at least one of whom opened fire.

The owner of the site, who was not present at the time, has been detained for questioning while arrest warrants have been issued for three Greek foremen.

Source: Agencies