Protesters in a Guinean opposition stronghold threw stones at the prime minister's convoy on Tuesday, AFP news agency reports the government as saying.
According to the statement, Prime Minister Ibrahima Kassory Fofana was travelling in the Fouta-Djalon region of northern Guinea when his convoy was attacked, causing several injuries, AFP adds.
The 82-year-old President Alpha Conde is running for a third presidential term in the 18 October election after he pushed through a new constitution, allowing him to reset the two-term presidential limit to zero.
Opposition to that possibility led to a wave of protests last year during which dozens of people were killed.
At least 50 people in protests
The human rights organisation Amnesty International says at least 50 people have been killed, mostly shot dead, in Guinea during protests in the last year.
Most of these protesters were killed during demonstrations against a third term for President Alpha Condé.
In a new report, Amnesty accuses defence and security forces of being responsible for the killings and says they are acting with impunity.
The report also documents 200 people who were injured during protests and 70 arbitrary detentions.
Amnesty called on the authorities to investigate and prosecute those responsible.
Presidential elections in Guinea are due later this month