Rizki, 29, is wooing passersby outside a bar in a red-light district near Jakarta, the Indonesian capital. In her five years as a commercial sex worker, she has always urged clients to use a condom to avoid HIV infection. "About 70% of my customers use condoms," she said. "Some men get angry when I ask, but most comply."

HIV is spreading more quickly than before, but the government's campaign to promote condom use among people at high risk of infection has once again been criticised by religious groups. Social stigma and sexual taboos are major obstacles in fighting Aids and HIV in Indonesia, which has the world's largest Muslim population.

"If members of society engage in risky sex, we need to give them religious and reproductive health education," the health minister, Nafsiah Mboi, said in a YouTube video posted on 19 June. "But if they still do it, what we can do is urge them to use condoms to reduce the risks."

Prevalence is at only 0.2% of the country's 238 million people, but the number of new HIV infections rose sharply from 7,195 in 2006 to 21,031 in 2011, the latest health ministry report says.

Since 2006, the government's "100% condom use" approach has come under fire, and in some areas discussion of the topic has faced explicit hostility in the context of commercial sex work. Mboi was summoned to parliament on 25 June, following accusations by conservative Muslim groups that her condom message was promoting promiscuity.

The health ministry estimates that 200,000 people are infected with HIV and 6.4 million people are at risk. In most provinces, HIV is largely concentrated among people with high-risk behaviour, but infections are rising among mothers and children, according to the National Aids Commission.

More than 75% of new infections occur in heterosexual people – up from 38.5% in June 2006 – while 16.3% occur among injecting drug users and 2.2% among men who had sex with men.

In May, the deputy chair of the Indonesian Child Protection Agency, Asrorun Ni'am Sholeh, urged the government to restrict sales of condoms to prevent access by teenagers. "There were reports that youngsters as young as 13 bought condoms from the neighbourhood convenience stores – I don't think those teenagers bought condoms for their parents," Sholeh said. "Premarital sex among adults should not be allowed, let alone among children."

Amidhan Saberah, chairman of the Indonesian Council of Muslim Scholars, said condom promotion should only be targeted at married couples. "The availability of condoms can encourage young people to engage in promiscuity," he said. "This is dangerous."

Despite the opposition of conservative groups, condom sales have increased from 95 million in 2006 to 195 million in 2011.

"A few years ago, my office was frequently demonstrated against by those who accused us of promoting promiscuity because we promoted the use of condoms," Mboi said in early June, when she was still secretary of the National Aids Commission.

"Growing religious conservatism in recent years means some red-light districts have been closed, but unregulated [sex work] is rampant – there's [sex work] in every harbour in the archipelago," she added.

Since 2004, the Global Fund to Fight Aids, Tuberculosis and Malaria has disbursed almost $400m to Indonesia. Although some provinces have started funding their own programmes, there are worries that developed countries may reduce aid to middle-income countries such as Indonesia during the economic crisis, which could undo the progress made.

Mboi said the Global Fund's contribution was vital in helping Indonesia fight HIV. "If the funding is stopped now, I think it will be a disaster for some areas."