(Updates death, wounded tolls, adds Paktia blast)
HERAT, Afghanistan, Aug 18 (Reuters) - A roadside blast killed 20 people and wounded at least 12 travelling in two minibuses in the western Afghan province of Herat on Thursday, provincial authorities said.
The vehicles appeared to have been hit by either a land mine or another type of roadside explosive, said Mahiuddin Noori, spokesman for the Herat provincial governor.
Noor Khan Nikzad, a spokesman for the Herat police chief, put the toll at 20 dead and 12 wounded.
Another blast in the same area wounded four civilians, Noori, the governor's spokesman, said.
In Gardez in eastern Paktia province, a suicide bomber blew himself up at the entrance to a NATO-run base, killing two Afghan guards, a spokesman for the NATO-led International Security Assistance Force (ISAF) said.
"There is an ongoing assessment but there are no reports of ISAF casualties," Lt. Col. Wayne Perry said.
The Taliban claimed responsibility for the bombing, saying the 70-year-old suicide bomber killed 27 and wounded 34, spokesman Zabihullah Mujahid said. (Reporting by Sharfuddin Sharafyar in Herat and Mirwais Harooni in Kabul; Editing by Bryson Hull and Ron Popeski)