Indonesian prosecutors on Tuesday sought a seven-month jail term for a US retiree accused of blasphemy after he allegedly pulled the plug on a mosque loudspeaker during a prayer reading.

The August 22 incident in the middle of the Muslim holy month of Ramadan resulted in retired Californian engineer Gregory Luke, 64, needing a police escort from his home on Lombok island as a mob tore it to pieces around him.

Prosecutors said Luke had blasphemed against Islam, the dominant religion in Indonesia, when he allegedly barged into the mosque to complain that a nightly Ramadan prayer reading was too loud.

"We recommend a sentence of seven months' jail as he is guilty of blasphemy and committing an act of hatred," prosecutor Baiq Nurjanah told a court in Praya, Lombok.

She said the maximum sentence of five years in jail was not being sought because the defendant, who runs a guesthouse for tourists on the island, had "expressed regret of his act".

Wearing a sarong, polo shirt and black Muslim hat, Luke asked the judges for the lightest sentence possible and apologised for his "wrongdoing".

"I apologise for my wrongdoing in the mosque. I've followed all the trial proceedings and listened to the witnesses' testimonies. I hope I can get the lightest sentence," he said.

Luke has previously denied pulling the plug on the loudspeakers used to broadcast the call to prayer -- a feature on most mosques in Indonesia.

In comments to the local media, he has said he went to the mosque to ask for the volume to be turned down when he was set upon by a group of local youths, who pushed him to the ground and pelted him with rocks.

A mob then chased him to his home and ransacked it as police looked on, apparently unable to intervene.

No one has been charged with any offence related to the mob attack on his house.