Indonesia is preparing to execute several prisoners, a police official said, though authorities have not said if foreigners will be among them.
It comes a year after the execution of foreign drug traffickers drew widespread condemnation.
President Joko Widodo's administration has pledged to resume executions by firing squad at a prison on Nusakambangan Island, despite criticism from rights groups and foreign governments.
"We have had a warning since last month to prepare the place," said Central Java provincial police spokesman Aloysius Lilik Darmanto.
"We carried out some rehabilitation of the location like painting and repairs because there will probably be more people who will be executed," he said, adding that the firing squad had been training and receiving counselling.
He declined to say how many prisoners would be executed, or when, or if there would be foreigners among them.
Authorities executed eight drug traffickers in April last year including seven foreigners, drawing condemnation from Australia and Brazil which had pleaded for their nationals to be spared.
Authorities have not given a breakdown of the numbers of foreigners on death row but citizens of France, Britain and the Philippines are known to be among them.
A 59-year-old British woman, Lindsay Sandiford, was sentenced to death after being convicted in 2013 of trying to smuggle cocaine worth US$2.5 million into the country.
A Philippine maid, Mary Jane Veloso, got a last-minute reprieve last year in response to a request from Manila after an employment recruiter, whom Veloso had accused of planting drugs in her luggage, gave herself up to police in the Philippines.
Her lawyer said he hoped she would not be in the next batch of prisoners to be executed.
"The execution of Mary Jane should be delayed because we are waiting for the legal process in the Philippines," said lawyer Agus Salim.
A lawyer for Serge Atlaoui, a French national, said authorities had not contacted the French embassy on whether his client would be executed in the next batch.
The government typically informs the embassies of foreign convicts days before their executions.
Indonesia imposed a moratorium on executions for five years before resuming them in 2013. It has executed 14 convicts, most of them foreigners, under Widodo.
But amid international outrage last year, scheduled executions were postponed while the government focused on reviving the economy, officials said.
Indonesia's representative at a UN narcotics conference was jeered last month when he defended the use of capital punishment for drug offences.