The official results of last weekend's elections in Montenegro have confirmed that the long-ruling pro-Western party of Prime Minister Milo Djukanovic won most votes — but it must seek an alliance to form the next government.

The State Election Commission said Wednesday that the Democratic Party of Socialists won 36 seats in the 81-member Parliament, followed by the opposition Democratic Front with 18 seats, and the Key Coalition with nine seats. The rest is taken up by several smaller parties and groups.

Opposition parties complain that Sunday's balloting was marred with irregularities, including the blocking of popular messaging services WhatsApp and Viber. The election was also marked by the arrest of 20 Serbs suspected of planning attacks.

Djukanovic seeks EU and NATO integration, while most opposition groups are pro-Russian.