Thousands of people have massed in Congo's capital Brazzaville in an opposition protest against plans by veteran ruler Denis Sassou Nguesso for a constitutional referendum that would let him extend his rule.
Sunday's rally was the biggest since Sassou Ngeusso returned to power in 1997.
If the referendum is approved, Sassou Ngeusso would be eligible to contest elections next year.
The former rebel leader announced last Tuesday plans for the referendum but gave no dates.
The 72-year-old president had previously convened a "national dialogue", which came out "by a large majority" in favour of amending the constitution to remove an upper limit on the age of presidential candidates as well as the number of terms the head of state can serve.
The changes effectively pave the way for him to stand for a third term in 2016. Opponents have branded the forum's conclusions a "constitutional coup".
Sassou Ngeusso was president from 1979 until 1992. He then served as opposition leader and returned to power at the end of a brief civil war in 1997 in which his rebel forces ousted president Pascal Lissouba.