Complex sentence: At least three of its soldiers were killed and 16 were wounded before the relief mission was forced to retreat, as the rocket and strafing attacks of the helicopter gunships also failed to dislodge the guerillas.
Split into simpler sentences: At least three of its soldiers were killed and 16 were wounded before the rescue mission was forced to retreat. Rocket and strafing attacks of the helicopter gunships also failed to dislodge the guerillas.