Dutch voters on Wednesday rejected a key EU-Kiev pact in a referendum seen as a barometer of anti-EU feeling, but it was not immediately clear if enough people had taken part for the ballot to be valid, exit polls showed.

Some 64 percent of those who voted said "no" to the deal, but the polls, with a margin of error of 3 percent, showed only 29 percent of eligible voters had taken part, according to public broadcaster NOS. Thirty percent of registered voters must cast their ballots for the polls to be valid.