Wedding nightmare as guests stuck in Bali - but bride and groom can't get there

A Perth couple were devastated after forced to cancel their Bali wedding when flights were grounded due to volcanic ash cloud.

Breana Napper and Josh Major had planned to get married in the seaside town of Sanur in the southeast of the island with 60 guests on Saturday.

But on Wednesday, authorities raised the alert for the volcano Mount Agung to the highest level as it spits ash into the sky and all flights have been cancelled.

The couple were meant to fly out from Perth airport on Wednesday with many of the guests, but Ms Napper told Yahoo7 some of their guests had already flown to Bali and were now left stranded as she frantically tries to reorganise the wedding in Perth.

"They now can't get home," she said. "There is an aunty, uncle and three cousins over there already."

"We spoke with our wedding planner and she's highly doubtful we'll get anything back, so we've basically lost $25,000 and paying for a second wedding on Saturday," Ms Napper said.

Government volcanologist Gede Suantika said the Mount Agung eruption would be “in hours, not days, because it’s already erupting”.

Denpasar Airport is expected to remain closed on Wednesday and airlines say there's no knowing when flights will resume.

Some carriers have warned passengers the crisis could run into at least next week.

Australian travel insurance companies have also warned customers would only be covered if they bought policies up to nine weeks ago - before warnings were issued by the Indonesian government.