He said: "But we still continue to recover as many bodies as possible."
The combatants had been fleeing military forces around the Kajaki district, where Afghan security forces and foreign troops have been fighting them since early March in an operation called Achilles.
Azimi said: "They were running from our troops to safe places across the river."
In a related development, 34 suspected Taliban members have been killed in the last two days in several gun battles in the southern province's Kajaki district.
The area is near where a US helicopter went down on Thursday, killing five Americans, a Canadian and a Briton.
An interior ministry statement said four Taliban commanders were among the 34 killed.
The defence ministry said two Afghan soldiers were killed and two wounded in the operations.
Elsewhere, Taliban fighters attacked a local police commander's home early on Saturday, killing five of his family members and sparking a gun battle with police that left 10 Taliban dead.
The attack in the southeastern province of Ghazni killed the policeman's wife, two sons and two nephews.
The commander worked for Afghanistan's auxiliary police, a system of back-up officers who supplement the country's regular police force.
Other auxiliary police called to the scene fought with the fighters, killing 10 of them.
The attack came one day after Taliban fighters targeted the home of a police official in the eastern province of Paktia.
Six fighters were killed in the assault.