An Afghan official says roadside bombs have struck two vehicles filled with passengers, killing three people and wounding 15 in a volatile southern province.

Mohammad Mayan, spokesman for the governor of Uruzgan province, said Tuesday that three of those wounded in Tuesday's attack are children and six of the wounded are in critical condition.

The Defense Ministry says the two vehicles were Land Cruisers operating as public transport, each carrying a large number of people.

No one has claimed responsibility for the attack, but the Taliban have a strong presence in the area and frequently use roadside bombs to target security forces.