In the lobby of the House of Print, Grozny's nine-storey press building, there used to be eight or ten gas masks in a box. I remember thinking that it wasn't many for such a big building, and being told, jokingly, that if something bad was to happen, the masks were only for the security personnel. I thought about those gas masks last week, as pictures of the House of Print on fire appeared on the internet.

At 12.25 a.m. on Thursday 4 December, a Chechen girl I know was woken by the noise. She lives in the centre of Grozny, off Prospekt Putin. She ran to the window and saw police cars speeding past. A friend of hers in another part of town posted an audio recording on WhatsApp. ‘I realised that the noise was coming from different places,’ she said. ‘I thought a kind of small war had started.’

Soon a video was circulating. In it, a young man, his face half lit, urged people to stay at home. He said that he and his comrades were mujahidin from the Chechen wing of the Caucasus Emirate: ‘We are stronger than ever. We came for our Muslim sisters. No one can touch them.’ (In September, the police in Grozny had detained a woman wearing a hijab that covered her forehead and chin. Ramzan Kadyrov, the Kremlin-backed president of Chechnya, later said that women and men dressed ‘in a Wahhabi style’ would be detained and questioned on suspicion of being linked to the insurrection in the North Caucasus.) ‘This is a martyrdom operation,’ the man in the video said. ‘And we will fight to the death.’

But were the insurgents really ‘stronger than ever’? For the first time, the head of the Caucasus Emirate is not Chechen and the focus of the insurrection is believed to have moved to Dagestan and Ingushetia. As for the size of last week's operation, it was unclear. A local journalist told Ekho Moskvy radio there had been 100 to 200 fighters scattered throughout the city; Chechen officials claimed there were far fewer fighters and that they were all killed. According to Russia's Anti-Terrorism Committee, insurgents arrived in Grozny at around 1 a.m., killing three police officers at a checkpoint before occupying the House of Print. Six of the gunmen were killed by security officers inside the building, which was gutted by fire. Others were found in School No. 20, where fighting continued later on Thursday. Russian and Chechen officials said that ten police officers and nine militants were killed. Other sources said a civilian was killed in the House of Print, quoting witnesses who said that the Chechen forces had fired indiscriminately, and used artillery.

Videos of the fighting could be seen on social media. One, almost abstract, shot at night, showed a rain of gunfire. Others showed fighting on Grozny's main roads. A friend sent me a video asking if I recognised where it had been shot. Men were taking cover from gunfire in front of a house where I stayed last summer. A neighbour had also been filming from her window. Later, I was sent photos of burnt buildings and dismembered bodies lying in the street.

‘In December,’ a Chechen man told me, ‘we all start to remember what happened twenty years ago, the start of the first war. The prelude actually happened in October or November. I was 14 at the time. On my way to school I saw tanks and burnt bodies scattered all around. Russian soldiers had been sent secretly, just like today in Eastern Ukraine, in hope of a quick victory... I think these fighters wanted to convey the message that they are not gone, that the war is not over, that they are here and ready to fight. It's pointless, of course, but in Chechnya there's a cocktail that is favourable to violence: oppression, poor education, poverty, a huge difference between the rich and the poor, religious influence and no rule of law. As long as the situation doesn't change, I fear we'll see more of this.’

Joanna Paraszczuk, a journalist who writes about Russian-speaking militants in Syria and Iraq, says that terrorist attacks could intensify in Chechnya. ‘In October, five police officers were killed in a suicide attack right outside a concert hall in the city. The attack happened just as a concert to celebrate Grozny City's Day was beginning.’ It was also Kadyrov's birthday.

‘I feel sorry for both sides,’ one young Chechen told me. ‘I do not think the fighters are not right. But I hope this will never happen again. Some people are angry. They say they are tired of this shit, but most people are afraid, they feel nothing.’