NICOSIA, Cyprus (AP) _ Iranian rebels claimed to have destroyed parts of Iran's giant Abadan oil refinery and attacked military bases in a campaign apparently timed to coincide with Friday's presidential elections.

The claims by the Iraq-based Mujahedeen Khalq, the main Iranian rebel movement, could not be verified.

But Iran's official Islamic Republic News Agency, monitored in Cyprus, quoted an ''informed source'' at Abadan as saying the report was a ''sheer lie.''

The rebels group said its fighters stormed the Abadan complex in southwestern Khuzestan province at 6 a.m. and killed dozens of defenders.

The group said the guerrillas detonated 16 bombs that demolished parts of the complex, which was the largest in the world before it was seriously damaged in the Iran-Iraq war of 1980-88.

The rebels also claimed to have blown up Iranian military installations and killed or wounded 200 Iranian Revolutionary Guards in five other attacks Friday in border provinces.

A Mujahedeen Khalq spokesman, Ali Safavi, told The Associated Press that at least one rebel was killed.

The raids appeared timed to coincide with the presidential election, which is expected to give Hashemi Rafsanjani a second four-year term. The Mujahedeen Khalq urged Iranians not to vote.

The attacks also may be part of a campaign to wreck the country's fuel supply system. Guerrillas have claimed to have destroyed a score of oil pipelines in and around Abadan in recent weeks.

Fuel shortages would worsen a bleak economic situation in Iran that has been blamed for widespread unrest. Tehran has confirmed many of the raids.

Safavi said the western section of the Abadan complex was gutted by the explosions and subsequent fires.

Before the Iran-Iraq war, the refinery had a capacity of 630,000 barrels a day. It resumed limited production in 1989 and has been processing 230,000 barrels of oil a day.

Increasing raids by the Mujahedeen Khalq have escalated tensions between Iran and Iraq, which still have not signed a peace treaty. Baghdad has denied Iran's charges that the rebels are staging attacks from bases in Iraq. Iraq, in turn, claims Tehran is aiding Shiite Muslim rebels in southern Iraq.