(Adds background, details, paragraphs 5, 18)

By Dan Whitcomb

CAMP PENDLETON, Calif., Aug 30 (Reuters) - A U.S. Marine testified on Thursday he shot to death two unarmed Iraqi men in the town of Haditha and watched members of his squad kill more civilians after a roadside bomb ripped apart a fellow Marine in November 2005.

Lance Cpl. Humberto Mendoza told a military hearing at Camp Pendleton Marine base in Southern California that he helped squad members "clear" nearby Iraqi houses after Lance Cpl. Miguel "T.J." Terrazas died in the bombing.

Mendoza was the first witness to testify against Staff Sgt. Frank Wuterich, accused of being the ringleader of troops who prosecutors say massacred two dozen unarmed men, women and children in Haditha in retaliation for the death of Terrazas on Nov. 19, 2005.

Mendoza conceded he had never seen Wuterich fire his weapon in the houses. Asked by defense attorney Maj. Haythem Faraj what he thought of his former squad leader, Mendoza responded, "I think he's a great Marine, sir."

The Haditha killings and abuses by U.S. soldiers in other Iraqi towns and at the Abu Ghraib prison caused outrage in Iraq and internationally. Mendoza was not charged in the case and has been granted immunity in exchange for his testimony.

The hearing is expected to last several days and will determine whether Wuterich, 27, should face a court-martial.

Wuterich wore his Marine-issue fatigues and was supported in court by his parents, who traveled to California from his Connecticut hometown for the hearing, and his wife.

Defense lawyers say the civilians died during a chaotic house-to-house battle in the western Iraqi town.

'I GOT SCARED'

Mendoza was riding in a vehicle with Wuterich when the bomb exploded and he joined the squad leader and two other Marines, Cpl. Hector Salinas and Lance Cpl. Stephen Tatum, in "clearing" nearby Iraqi homes.

Mendoza said that at the first home, Salinas gunned down an elderly Iraqi woman. Mendoza said he found an Iraqi man in another room, reaching into a closet, and shot him repeatedly.

"I got scared thinking he was trying to get a weapon so I started shooting," he said. "After all those rounds, I was pretty sure he wasn't going to get up."

At the next house, Mendoza said, Wuterich knocked on the front door and said, "Just wait until he opens the door and shoot."

The front door never opened, Mendoza said, but the kitchen door did and he shot a man who was peeking out.

At the second house, Mendoza said Tatum told him to shoot a group of Iraqi women and children he found on a bed in a closed room. Mendoza said he walked away but saw Tatum return and heard a loud noise, possibly gunfire or a grenade.

The women and most of the children were later found dead.

Defense attorney Faraj suggested in cross-examination it was Mendoza who killed the women and children in the room, a line of questioning that angered prosecutors.

Military authorities have dismissed charges against two Marines, Lance Cpl. Justin Sharratt and Capt. Randy Stone, citing battle conditions against a "shadowy" insurgent enemy.

Murder charges were dismissed in April against Sgt. Sanick Dela Cruz in exchange for his testimony and he was expected to take the witness stand for prosecutors on Friday.

Four other Marines have still to be dealt with.

AlertNet news is provided by