Security in Iran's main oil producing province of Khuzestan deteriorated today after a series of gun battles between Iranian Arabs and Revolutionary Guards and further acts of sabotage.

Twelve Revolutionary Guards and two Iranian Arabs were reported killed during the night in fighting on Minoo Island off the oil refining center of Abadan, according to the head of the Iranian Arab community, Ayatollah Mohammed Taher Shobeir Khaaqani.

It was the second shootout for the island's Revolutionary Guards, who seized a boatload of Soviet-made RPG-7 bazookas Tuesday night after a gun battle in which three are said to have died.

In a separate development, a train carrying 800 passengers derailed in the desert 37 miles east of the capital, killing at least nine persons and injuring more than 100, the state-run radio reported.

The radio said the train, on its way from Tehran to the Moslem shrine city of Mashad in northeastern Iran, went off a stretch of track that was not properly fastened. Asked if he suspected sabotage, a railroad official said further investigation was required to determine the cause.

The governor of the southwestern port city of Khorramshahr, Mohammed Alavi, today reported heavy nighttime shooting between Revolutionary Guards and Arab gunmen who he said attacked two police stations, a service station and guard posts at the main bridge over the river that divides the town.

Independent accounts of these gun battles have not been available, but they conform to a pattern of escalating violence in the province which officials fear may erupt into wider intercommunal strife.

Fears that Iran's oil installations have already become the target of guerrilla action arising from the struggle were confirmed today by the governor general of Khuzestan, Admiral Ahmad Madani.

He said an explosion Wednesday that ruptured a crude oil pipeline running from one of Iran's major oil fields to its biggest refinery at Abadan was caused by machinegun fire that punctured the pipeline and ignited a blaze that took four hours to extinguish.

No cause has been established for an earlier explosion that damaged eight or nine pipelines linking the refinery to an export terminal at Bandar Mahshahr.

The Iranian government apparently has not responded to a request by the head of the National Iranian Oil Company, Hassan Nazih, for troop reinforcements to increase security for the oil production and export facilities.

Meanwhile,a bomb explosion just outside Khorramsharh yesterday damaged a railway bridge linking the town to the provincial capital of Ahwaz.

The explosion occurred early in the evening, but heavy shooting kept repair teams from reaching the bridge for several hours. A second bomb on the bridge apparently failed to detonate.