Twelve people were arrested on Monday evening at a cinema in India, after they remained seated while the national anthem played.
The cinemagoers, who were attending an international film festival in the city of Trivandrum in Kerala, were later freed but they face charges of "failure to obey an order issued by a public servant, thereby causing obstruction or annoyance to others".
And at a cinema in Chennai on Sunday, eight people who did not stand for the anthem were assaulted and abused, police said. The eight were later charged with showing disrespect to the anthem.
The arrests and reports of assault follow last month's Supreme Court ruling that the national anthem be played before every film and that audiences stand while it is played - and they make it clear that authorities are taking the ruling seriously.
"If we did not sit on chairs, I thought we would lose the seats," one detainee told the Indian Express.
The controversial ruling - cheered by the ruling Hindu nationalist BJP - comes at a time of routine demands on Indians to display patriotism, and this is not the first time people have been targeted for not respecting the national song.
In October, a disabled man who had been carried from his wheelchair to a seat, described how he was assaulted by other members of the audience for not standing for the anthem.
In the past three years, people have been thrown out cinemas and even charged with sedition for not standing up for the anthem.
A 1971 law makes any obstruction to the singing of the song "or causing disturbances to any assembly engaged in such singing" punishable by a three-year prison term and/or a fine.
But October's Supreme Court ruling gives national authority to what was previously a rash of loosely-followed, state-specific laws.
The ruling says that the anthem must be played in all cinemas, accompanied by an image of the Indian flag, and everyone must stand. It also stated that the doors must remain closed to prevent people from entering or leaving. The court later amended the ruling to exempt disabled people.
Critics of the Supreme Court ruling have called it a case of judicial overreach and an attack on freedom of expression.
Political scientist Suhas Palshikar said the ruling threatened to turn "citizens into subjects". Gopalkrishna Gandhi, a former diplomat, wrote: "The national anthem is not a traffic signal that has to be respected. It is not a tax that requires compliance. It is not a test that has to be submitted to."
National anthems are seen as tests of patriotism around the world. In Japan, school teachers have been warned for not standing up during the anthem. In Mexico, a woman was fined for mixing up the words.
And in the US, the Star-Spangled Banner has a long-standing association with protest. In September, American football player Colin Kaepernick said he had received death threats over his refusal to stand for the anthem in protest against the treatment of black people by police.
"Some of the right, committed to nationalistic politics, naturally see the anthem as a vital issue," Kevin Kruse, a professor of history at Princeton University, told me. "This has been true in past moments too, especially in times of war - the anthem being politicised during the Vietnam era, for instance, leading to the 1968 Olympics protest."
But what is unsettling in India, said political scientist Suhas Palshikar, is that state-ministered patriotism "often tends to give way to unruly vigilantism or authoritarian state machinery, or both".