4 pilots killed as two Philippine military planes crash during training

Two military planes crashed mid-air during training at an air base in the Philippines, killing four pilots, the air force said Saturday.

The SF-260 single propeller planes crashed at Fernando Air Base, south of Manila, on Friday afternoon.

"Both aircraft went down within the base perimeter, with no other casualties reported," Philippine Air Force spokesman Colonel Alvin Capinguian said in a statement.

An investigation was opened to determine the cause of the mishap, and Capinguian said the air force's fleet of SF-260s has been temporarily grounded as a precaution. 

There have been a number of deadly crashes involving Philippine military aircraft in recent years. 

In May, two military pilots were killed when another SF-260 plane crashed during a training flight in Benguet province in the northern Philippines.