The European Union is preparing to impose an arms embargo and visa ban to punish Guinea's military rulers for last month's massacre at a pro-democracy rally.

An official who spoke on condition of anonymity because the official decision still has to be taken said Thursday the EU is still drawing up a list of Guinean leaders to be included on the visa ban list.

EU officials also are looking at whose assets should be frozen. Once completed, a meeting of EU foreign ministers in Luxembourg starting Monday will impose the sanctions.

The peaceful pro-democracy rally in Guinea took a violent turn late last month when presidential guard troops opened fire on tens of thousands of demonstrators. A Guinean human rights group says 157 people were killed.