Witnesses say a 21-year-old man has been killed by gunfire in Guinea's capital amid growing tensions between security forces and opposition supporters.

The opposition had declared a general strike Monday in the capital of Conakry to express their anger with the outcome of recent legislative elections.

Security forces fired tear gas at demonstrators in the Hamdallaye neighborhood where protesters had lit tires on fire to block traffic.

Aziz Bah said his 21-year-old adopted son Mamadou Bailo Diallo, was out to buy water when a police officer shot him.

Guineans voted in hotly contested legislative elections in late September and it took officials weeks to release the results.

Official results show President Alpha Conde's party won 53 of 114 parliamentary seats, while the main opposition party took 37.