The EU official's comments followed a strike in Guinea called to protest the crackdown.
Thousands of Guineans stayed indoors on Monday and Tuesday to mark the killings, bringing the capital, Conakry, to a standstill.
The strike also froze production in the country's mining operations, halting work at an aluminium refinery and freezing bauxite exports, a major source of Guinea's foreign exchange.
But mining company officials said work had resumed on Wednesday, the Reuters news agency reported.
September's crackdown began when government soldiers opened fire at protesters who had gathered outside a stadium in Conakry in defiance of a ban on the rally.
The protest followed speculation that Camara, who seized power in a coup last December, would stand in next year's elections.
Camara has said he is not responsible for his troops' actions.
Rights organisations and the UN say the number of people killed in the crackdown may have been higher than 150 and that at least 1,200 people were injured.
The military government puts the death toll at 56.