Thailand's constitutional court has rejected the general elections held last month.

It says the vote was unconsitutional because elections weren't held in several constituencies.

The announcement is a major setback for Prime Minister Yingluck Shinawatra's government.

The ruling party has been trying to stop the opposition protests that first started in November, over plans for a new amnesty law.

Al Jazeera's Zeina Khodr reports from Bangkok.