Almost 7,000 “Islamophobic” tweets were sent, in English, every day in July worldwide, data seen by the BBC suggests.
This compared to 2,500 in April, with peaks recorded following the Nice lorry attack and the attempted military coup in Turkey.
Forty-nine words and hashtags were used as indicators of anti-Islamic tweets, by the think tank Demos.
Twitter said it was “continuing to invest heavily” in preventing abuse.
Demos analysed tweets recorded between March and July, and judged there to be 215,247 tweets – sent in English – that were “highly likely” to be anti-Islamic, derogatory or hateful.
The vast majority of tweets that could be located to Europe came from the United Kingdom, with other concentrations in the Netherlands, France and Germany.
The highest number of “Islamophobic” tweets to be sent in one day, 21,190, came on 15 July – the day after a man ploughed a lorry into crowds on the seafront in Nice, killing 85 people. Jihadist group Islamic State (IS) claimed one of its followers carried out the attack.
Other peaks came on 17 July, the day after an attempted coup in Turkey, in which 10,610 such tweets were sent, and on 26 July – the day a Catholic priest was murdered by militant Islamists in a church in the French city of Rouen. IS subsequently claimed the church attackers had pledged allegiance to them.
Higher numbers of anti-Islamic tweets were also seen in the days following an IS-claimed suicide attack on the Iraqi capital, Baghdad, that claimed more than 250 lives on 3 July – with 9,220 such posts on 5 July – and the day after shootings in Dallas, US, in which five police officers were killed. The gunman, Micah Xavier Johnson, was not a Muslim.
While other factors could have added to these two spikes, Demos said, these events were the most likely causes.