BILOXI, Miss. » More than one witness told a jury Wednesday that he was ordered to strip naked with the rest of his basic training group and crowd into a shower area so small that it was impossible to avoid touching.

There were 50 or more trainees in the group and one witness described the shower as an 8-by-10-foot room.

The prosecution called six witnesses Wednesday afternoon in the court-martial of the drill sergeant who is accused of ordering the trainees to strip.

On trial is Tech. Sgt. Bobby D. Bass, accused of cruelty, wrongful sexual contact and assault during his time as a basic training instructor in 2009 at Lackland Air Force Base in San Antonio.

The military trial is being held at Keesler Air Force Base in Biloxi because Bass is stationed at Keesler. It is the first case connected with last year’s sex scandal at Lackland to be tried somewhere other than Lackland, the base that handles basic training for the Air Force.

Bass is also accused of forcible sodomy and having an unprofessional relationship with a man he supervised while deployed to Kyrgyzstan in 2007 and 2008.

During opening arguments, the prosecution, led by Capt. Matthew Neil, painted a picture of a former drill sergeant who, while deployed, hid liquor in a mouthwash bottle, drank with a man under his supervision and took sexual advantage of him while he slept.

At Lackland, the abuse was different, Neil told the jury of two officers and six enlisted. At Lackland, he said, trainees were abused because they were vulnerable.

He said the prosecution will attempt to prove that Bass “takes satisfaction in imposing his power on young, male airmen.”

Bass’ defense, lead by Capt. Antoinette Quinn, told the jury that the charges against Bass while he was deployed are unrelated to the Lackland charges and urged the jury to watch for inconsistencies in the testimony of the 20 Lackland trainees who would be giving their separate accounts of some of the incidents.

The testimony Wednesday centered on a group of trainees in Lackland in the fall of 2009, when Bass was certifying a new drill sergeant. Both oversaw the group of 50 to 60, called a band flight because the members could play instruments.

The first to testify was Tech. Sgt. James McBride, the new drill sergeant. He testified with immunity from prosecution and told the jury that at times, Bass sent him home or allowed him to run errands when some of the alleged hazing and misconduct occurred, but he did describe a distraught group of trainees upon his return after what prosecutors call the shower incident.

The other five witnesses, three still in the military and two now civilians, will not be identified because of the sexual nature of the charges.

Two in uniform blushed at times when telling their accounts.

The trainee witnesses said they did what they were told to do because they were afraid their basic training would be prolonged if they didn’t.

They talked of while being naked in the shower and in close quarters with bodies touching, being ordered to reach as high as they could and to bend over and touch the wall as low as they could.

One told of being called into Bass’ office and ordered to apply Icy Hot muscle cream to his genitals. He said he hurt for hours and was not allowed to wash it off.

Another said he was called into Bass’ office and given an option and chose the Icy Hot over taking the risk of having his basic training extended. He said washing it off would have made it worse.

All told of an incident where their trainee leaders were brought out in their underwear and ordered to do pushups while the rest of the group was ordered to mock and laugh.

One talked of being ordered to take multiple showers and shave all his body hair except for his arms and legs. Bass also ordered him to write his girlfriend an emotional break-up letter. Another told the jury Bass slammed him against the wall in his office.

None of Wednesday’s witnesses reported misconduct until investigators in the Lackland scandal case approached them several years later.

When asked if he thought the shower incident was out of line, one witness, several years older than the others, said, “I would not have stripped down naked and touched the same wall with the entire flight if I hadn’t been ordered to by an instructor.”

Presiding over the court martial is Lt. Col. Michael Coco.

Earlier this week he denied two defense motions — to dismiss the more serious sodomy charge because of the statute of limitations, or to sever it from the Lackland hazing charges.

If convicted, Bass will join several other drill instructors at the Air Force’s basic training base who have been convicted in what has become a scandal of sexual misconduct, rape, hazing and assault.

The Lackland investigation has grown to involve 33 instructors since it began last year.

The scandal has spurred a House inquiry and already brought down the basic training group commander at Lackland, one squadron commander and several senior enlisted leaders.