What could it be?

It was about 0055hrs on a Thursday night. That's 55 minutes past midnight for you folks who need the 'conversion'. We had been on the move for 5 hours. We came to a sugarcane plantation and the troops were given some rest before the final push to the objective. I was in a slight stupor as I had fallen asleep for less than hour. The occasional snoring can be heard as tired bodies take a much needed rest. Sentries are posted. The full moon is at its zenith and its brightness bathes the countryside with a soft glow. A soft cool breeze sweeps the landscape, a welcome relief from the afternoon blazing sun. The chirping of crickets are interrupted by the incessant howling and barking of mongrels, agitated by the presence of so many humans so close to their territories. I had decided to find a nice spot away from the troops to rest my aching shoulders. I moved to a nearby junction and fell asleep amongst a nice warm nook. I don't know why I woke up after less than an hour of sleep but there was a sudden chill... That was when I heard screams coming from the direction of the resting troops. Followed a commotion! It was followed almost immediately by a loud gunshot from one of the rifles. My first thought was that the ‘enemy’ patrol must have chanced upon the resting troops. But the screams were unlike any that I've heard before. They certainly did not sound like men screaming. It sent a chill down my spine! I half expected the troops to run out to the junction where I was. I immediately got up and ran in, followed by other umpires who were nearby. By the time we arrived, most of the troops and umpires were already wide awake, standing around and asking what had happened. The screams had emanated from inside the bushes where some of the troops had been resting. Some said they saw something dark running around while others said the rumbling ground was caused by a human wave of troops running out after the screams. Those who were not sleeping and were directly facing the vegetation where it happened said that they saw a ‘Mexican wave’ coming at them as the troops, upon hearing the screams, got up TOGETHER and ran out TOGETHER! The rifle shot was from one of the commanders where was afraid that a wild boar was running around amongst the troops. A panicked wild boar will mow down people in its path. But we were later told by one of the RTA liaison that there are no wild boars in the area... So what could be the source of the screams? There were a few suggestions put up. It could from one of the sleeping troops having a very bad dream and people around him panicking him upon hearing those ‘blood-curdling’ screams. Or it could really be a wild boar since wild boars are known to scream in that fashion especially before being slaughtered. Or it could be...