An American free-lance journalist was wounded today in a fire fight between government forces and guerrillas on the outskirts of El Salvador's capital today, witnesses said. The journalist's Salvadoran interpreter was killed in the same incident and a local photographer working for The Associated Press was also wounded.

The wounded American journalist was George Thurlow, who was on assignment for the Vacaville (Calif.) Reporter and the Santa Barbara News and Review. Thurlow, of Woodland, Calif., who arrived in El Salvador last week, was reported in fair condition tonight at the city's Policlinica Hospital sufferring from wounds in the left hand, arm and shoulder.

Eyewitnesses said Thurlow was injured when he, photographer Joaquin Romero Zuniga and interpreter Gregorio Moran rushed to the San Salvador working-class suburb of Aguas Calientes (Hot Waters), where a battle had been raging for two hours between elements of El Salvador's armed forces and National Guard and antigovernment guerrillas who apparently had infiltrated the area in an attempt to sabotage a local power station.

The three men were hit by gunfire, presumably fired by the government forces, when they tried to move up a street to get closer to the action. Moran was hit in the chest and apparently died instantly. Thurlow was wounded in three places and Romero Zuniga was hit in the upper right thigh.

Television crews from both the NBC and CBS networks, who also had rushed to the scene this afternoon, witnessed the shooting while pinned down behind their vehicles in the same suburb. None of the NBC or CBS crewmen was injured.

Manny Alvarez, a cameraman from NBC, described the situation in Aguas Calientes as "confused" and said the Army seemed to be firing in every direction and had claimed that there were suspected guerrillas firing on them from a nearby ravine.

According to Alvarez, Moran, Thurlow and Romero Zuniga, who had been crouching down near the NBC crew, decided to run down the road toward the firing. Alvarez said Moran asked if they were going too. "I said, 'no way,'" Alvarez recalled tonight. "And Morgan, who was leading the way, turned back and laughed at me. Minutes later he was killed and the others wounded before my very eyes."

Since January, when the left-wing guerrillas launched their ill-fated "final offensive" against the civilian-military junta that rules El Salvador, two foreign jounalists have been killed and four wounded.

Earlier, news services reported these developments :

In more political violence, heavily armed men pulled the director of the national lottery from his car this morning and shot him to death, the government said.

Carlos Hidalgo, 47, was shot four times in the chest just after he dropped his daughter off at her school, the government added.

No group claimed responsibility for the slaying, but family friends and Hidago had received death threats in recent weeks from the Farabundo Marti National Liberation Movement, a coalition of leftist groups seeking to overthrow the junta.