The British embassy in Jakarta, Indonesia, posts a picture on its Instagram account four days ago which shows a rainbow flag alongside the Union Jack.
Indonesia summoned Britain's ambassador on Monday over an LGBTQ flag displayed at the UK embassy, with Jakarta calling on foreign envoys to respect local sensitivities in a country where same-sex relationships remain taboo.
Gay sex is legal in the world's biggest Muslim-majority nation, except in one province, but there is widespread discrimination against the LGBTQ community and some gay Indonesians have been arrested under an anti-pornography law.
The embassy last week posted a picture on Instagram of a rainbow flag on its premises to mark the International Day Against Homophobia, Biphobia and Transphobia. It was accompanied by a message of support for LGBTQ rights.
A backlash ensued among conservative Indonesians online in response to the social media post and on Monday Jakarta's foreign ministry summoned British ambassador Owen Jenkins to explain.
"The action, along with the publication (of the picture) through the official social media account of the British embassy, is highly insensitive," ministry spokesman Teuku Faizasyah told AFP on Monday.
"The ministry would like to remind foreign envoys to respect the sensitivity of cultural and religious values," he added.
The embassy did not immediately respond to an AFP request for comment.
Influential conservatives had chastised the embassy for flying the rainbow flag alongside the UK's Union Flag.
The chairman of Indonesia's top Islamic scholars body, the Indonesian Ulema Council, said the diplomatic mission was disrespectful for openly supporting LGBTQ rights.
"We must reprimand them that as a guest, one must know their place and understand the norms in the country where they're at," Cholil Nafis wrote to his 68,000 Twitter followers on Saturday.
Same-sex relationships are illegal in Indonesia's conservative province of Aceh, where they can result in public flogging under local Islamic law.
Though tolerated elsewhere in the country, the LGBTQ community has faced growing pressure on their rights and freedoms.
Islamists and conservative lawmakers have tried to criminalize same-sex relationships and openly gay people often face discrimination.
Conversion therapy including exorcism to "cure" homosexuality is still common and gay sex is prohibited in the military.