"Hundreds of rockets are crisscrossing the sky," a western diplomat said by telephone from Baghdad yesterday as he stared out a window at the Iraqi antiaircraft barrages sent up to counter Iranian air raids on the Iraqi capital.

"There has been a hour and a half of absolutely incredible rocket firing visible from our windows," the diplomat said. The interview with The Washington Post was one of a number of eyewitness accounts that emerged of the dawn-to-dusk air assaults that plunged Baghdad into darkness and terror yesterday.

The waves of Iranian air raids began shortly after 6 a.m. and appeared to center on industrial sections of Baghdad. The chief target according to Western observers, seemed to be a major oil refinery located not far from the American diplomatic mission.

THE U.S. missions was not damaged nor were there reports of American casualties in Badhdad. Four Americans were reported killed in an Iranian attack on an oil refinery in Basra but there was no official confirmation. Eyewitnesses said last Baghdad's oil refinery apparently was not hit.

The last of six Iranian air raids came in the early evening hours long after the city was left without electricity. It was not known whether the blackout was imposed as a precautiounary measure by the government or whether Baghdad's power plant was damaged earlier in the day.

The last raid was under way at 7 p.m. One Western observer said by phone then that "there was virtually no traffic running in the city the city is absolutely black and there is no electricity."

Obervers said that they had seen one Iranian Phantom jet take a direct hit, presumably by a surface-to-air rocket, in the afternoon. An official Iraqi statement released in Washington said a total of 67 Iranian planes were downed yesterday, 35 of them over Baghdad.

An Iraqi journalist contacted by The Associated Press and that Iranian attacks intensified with the onset of darkness, leaving the sky over Baghdad "lit up by thousands of streaking shells form the antiaircraft batteries."

An official announcement said 18 persons were killed and 42 wounded during the first early-morning bombing raid on the Iraqi capital. There were no reports of casualties from subsequent assaults. Iranian planes also staged raids on nine other targets in Iraq, including the cities of Basra, Masul and Nineveh.

Another Iraqi journalist was quoted as saying 29 persons were killed at Basra where Iranian bombs hit a U.S.-operated petrochemical complex.Basra, on the southeastern tip of Iraq, is the main Iraqi port on the Shatt-al-Arab waterway disputed by the two countries.

But the journalist, Emah Nimah, was quoted as saying that Baghdad was calm yesterday morning and that "life went on as normal."

"Students were reporting to schools, shops and offices opened and I can see two or three persons swimming in the pool at the Baghdad Hotel," he was quoted as saying.

Later in the day, however, the situation changed and a curfew was imposed in late afternoon.

Iraqi sources were quoted as saying the Iraqis were monitoring Iranian radio reports and that these included "contradictory" orders.

"Tehran raido is easily heard here and no one takes any notice of it because today Iran is a mess," Nimah said. "Everyone there is saying something different."

A Tehran radio broadcast monitored in London quoted Iranian revolutionary leader Ayatollah Ruhollah Khomeini as saying that radio and television must boardcast only those reports "that are proven to be 100 percent correct" to prevent panic and anciety. He also warned Iranian newspaper against publishing articles that might weaken the morale of Iran's armed forces.

The ayatollah was also said to have ordered the security forces to arrest immediately "those who spread rumors, irrespective of who they are." Another Tehran radio broadcast charged that the United States and Iraq were in collusion seeking "to weaken our battle forces" and help "counterrevolutionary groups to split out ranks." It warned that many counterrevolutionaries are disguised as taxi drivers.