Twelve people have been killed in clashes between opposition supporters and security forces in Guinea's capital, Conakry, a government spokesman has said.

Government spokesman Albert Camara said on Monday that 26 people were also hospitalized with injuries from the violence that began last week, The Associated Press reported.

Hospital workers put the death toll higher, at 18, because some families took their dead from the morgue for immediate burial.

The clashes are the latest in a series of disputes between the opposition leader Cellou Dallein Diallo and the ruling party over the details of parliamentary elections scheduled for June 30.

The elections have been repeatedly delayed since 2011, and the last legislative elections were held in 2002 in the African nation.

The opposition leader has accused the government of President Alpha Conde of planning to rig the vote.