The top commander in Afghanistan on Wednesday issued updated rules that limit the use of artillery and airstrikes but recognize the right to use firepower in self-defense.

The rules issued by Gen. David Petraeus are broadly similar to regulations that had been issued by his predecessor, Gen. Stanley McChrystal, last year.

They are aimed at limiting civilian casualties.

Petraeus had pledged to examine how the rules were used when he took command of allied forces in Afghanistan.

Some troops had raised concerns that the restrictions on firepower had placed U.S. and allied troops at risk when fighting insurgents.

“I am keenly aware of concerns by some of our troopers on the ground,” Petraeus said at his confirmation hearing in June.

At the heart of counterinsurgency doctrine is the principle that winning over the population is the key to defeating insurgents. Civilian casualties can alienate the population.

“We must continue — indeed, redouble — our efforts to reduce the loss of innocent civilian life to an absolute minimum,” the new document says.