Reports from Iran say police have exchanged gunfire with militants following an explosion near a school in the southeastern part of the country.
Iranian news agencies said late Friday that police in the city of Zahedan cordoned off the neighborhood where the incident took place. Electrical power to the area was cut off. It is not clear if there were casualties.
On Wednesday, a car bomb blast in the same city killed 11 Iranian Revolutionary Guards.
A Sunni Muslim group, Jundollah, claimed responsibility for that attack. Officials say the group is linked to al-Qaida.
Zahedan is the capital of Sistan-Baluchistan province, which borders Pakistan and Afghanistan.
Iran has accused the United States of backing militants in the sensitive border area to destabilize the country.
Some information for this report provided by AP, AFP and Reuters.