Hundreds in Burundi are protesting against the ruling party's decision to nominate the president to run for a third term.

Burundi's police clashed early Sunday with protesters and blocked off some parts of Bujumbura, the capital. The demonstrations are in reaction to the decision Saturday of President Pierre Nkurunziza's ruling party to have him run in elections on June 26.

Watchdog groups warned of unrest if Nkurunziza decided to run again. Thousands of Burundians have already fled to Rwanda fearing pre-election violence.

Burundi's constitution stipulates that a president can only serve for two terms, but Nkurunziza's party says he is eligible for another term as popularly elected president because in his first term he was elected by the legislature. Critics say this is not a proper interpretation of the law.