The protesters, however, insisted they were not to blame for any damage.
Dimos Koumbouris, head of a pensioners' union who was among those who entered the ministry, said union representatives had gone into the building seeking a meeting with Vroutsis.
Reached by telephone while still at police headquarters, where he said a total of 35 union heads and representatives were waiting to be charged, he said it was police who damaged the doors in their attempt to arrest the unionists.
"There was no damage. ... why would we do any damage?" he told the AP, adding that they had wanted to meet the minister over social security reforms.The minister himself issued a statement saying the demonstrators had tried to occupy the ministry, a common form of protest in Greece. "The organized raid and attempt to occupy the Labor Ministry by force does not solve workers' problems," Vroutsis said. "Scuffles and the destruction of public property only cause sadness. I am sorry, because some people aiming to create impressions are setting up a scene of tension and violence." Strikes are to intensify in coming days, with public transport workers and hospital doctors to hold a 24-hour strike in the capital on Thursday. Port workers start a 48-hour strike the same day, leaving islands without ferry services. Other state-run services are also to be disrupted by work stoppages lasting several hours. Last week, the government used emergency powers to force Athens subway workers to end rolling strikes that lasted eight days. The Brussels-based European Trade Union Confederation strongly condemned the action taken by the conservative-led coalition government, noting that workers who defy civil mobilization orders face prison sentences of up to five years. "The wheeling out of emergency powers to enforce austerity policies is unacceptable," ETUC general secretary Bernadette Segol said in a statement.