A number of attacks have been claimed by IS recently but, in what appears to be their first attack in Turkey, 32 people were killed and more than 100 wounded in a suicide-bombing in Suruc, in a mainly Kurdish region on the border with Syria.
The bomb blew up in a crowd of young socialist activists preparing to take aid over the border to Kobane, which became a symbol of resistance against the jihadists, who were driven out of the city by Kurdish forces in January.
The attack came at an interesting time because Turkey has been heavily criticised for being a "poor ally" in fighting IS, Max Abrahms, a terrorism expert and professor at the US's Northeastern University, told RFI.
According to him, the attack was not so surprising.
"Over the past few weeks, Turkey seems to have changed its tune a bit," he said. "More and more, Turkey has engaged in a crackdown against the Islamic State, there have been dozens of arrests of IS sympathisers in the country, Islamist websites have been shut down,so there is a sense that Turkey is changing its behaviour towards the Islamic State, although it is too little too late."
This attack on its soil could encourage Turkey to get more involved in the fight against IS, he believes.
But there could be an alternative explanation to this attack, Abrahms said.
"The actual target inside Turkey was not the government but rather Kurds;" he explained. "The Kurds, particularly in Syria, are at war against the Islamic State and we saw that most vividly in the battle over Kobane. So many people believe we are not seeing change but continuity."
Some protests took place in Istanbul and Ankara after the attack and turned violent as police clashed with protesters.
Hundreds of people in Istanbul were chanting slogans accusing Turkish President Recep Tayyip Erdogan of collaborating with IS.
This is the general feeling among the Turkish Kurds, Aaron Stein, a Middle East security expert, said.
"Among them, especially those who have been affected by the war in Syria, there is a deeply felt belief that [Erdogan's party] the AKP and Isis [IS] are synonymous and that they cooperated with one another," he said. "There is little evidence but it is deeply felt."
The Turkish president has condemned the attack and, despite tense relations with Syria's Kurds, the Turkish government described the Suruc bombing as an attack against the nation.
An action plan on border security will be discuss Wednesday, so that the necessary measures can be taken, Erdogan told a press conference Tuesday.