Eleven people died and 28 were wounded when two suicide attackers rammed a car bomb into a government compound near the western city of Herat, the interior ministry said.
Provincial police chief Sayed Agha Saqeb told reporters that the bombers were being pursued by police when they detonated the vehicle at the entrance to the Guzara district compound along the road from the airport to the city.
"The car was under our surveillance. It was ordered twice to stop but they didn't stop," said the police chief.
The dead included three policemen and eight civilians, a provincial spokesman said.
Just hours later, four policemen died when three suicide bombers stormed their compound in the southern province of Helmand, a local government spokesman said.
Two of the bombers set off explosives strapped to their bodies and a third was shot dead by police guarding the Musa Qala police offices in the troubled province, Daud Ahmadi, the spokesman for the provincial administration, told AFP.
"Three suicide attackers entered the police compound in Musa Qala district of Helmand. Two of them detonated their explosives, one was killed by police," Ahmadi told AFP.
Police chief Abdul Wali and four others were wounded in the attack, he said.