Thousands of protesters called for Angola's President Joao Lourenco to step down during a rally in Luanda on Saturday organized by the country's largest opposition party to commemorate its late leader.

UNITA, a former rebel group turned political movement that lost the election last year, has said it wants to initiate a parliamentary process to remove Lourenco from office, accusing the 69-year-old of being "authoritarian". 

"Someone is responsible for famine, unemployment and the jailing of demonstrators. Who is he?" UNITA leader Adalberto Costa Junior asked a crowd of supporters waving red and green flags -- the party colors -- in Luanda.

"Joao Lourenco!" the protesters claimed.

The oil-rich southern African nation has experienced a wave of protests since the government cut subsidies for petrol in June.

The move was aimed at curbing government spending, as the economy suffers from a slide in oil prices that has weakened the local currency, the kwanza. But it resulted in unpopular sharp fuel price hikes. 

"We have a government that does not deserve Angolans," Costa Junior said.

Under Angola's constitution, the President can be removed from office if he is considered to have committed acts that threaten democracy.

But UNITA is yet to say when it intends to initiate proceedings against Lourenco.

Removing the president requires a two-thirds majority vote in parliament and support from the courts. Lourenco's ruling Popular Movement for the Liberation of Angola (MPLA) has dismissed UNITA's efforts to remove the president as "unserious" and "undemocratic".

Read more: Angola considering joining Russia’s Mir Payment System