A Swedish man on trial for allegedly planning to commit a suicide attack has denied the charges in court, Swedish Radio reported on Friday.
"I deny the charges, I've never had plans to harm anyone or make a bomb," the 20-year-old told the court.
The man, who was arrested in February, described himself as a Sunni Muslim, the report said.
In her opening statement, prosecutor Ewamari Haggkvist told the Attunda District Court near the capital of Stockholm that the defendant had wanted to set off an explosion in order to kill people and become a martyr.
She said the "planned criminal act could have seriously harmed Sweden," citing the indictment, according to the report from the court room.
Evidence in the case included seized materials that could be used to make a bomb, including six bottles of acetone, steel balls and a pressure cooker, Haggkvist added.
The man's attorney later said that only the packaging for a pressure cooker and steel balls was found - and not the items themselves.
The prosecutor also drew attention to the fact that the defendant was stopped twice last June in Turkey, where he had planned to travel onwards to Syria to join the Islamic State terrorist militia.
Prior to the trips he had become more and more interested in religion, especially Islam, and withdrew large sums of money.
When his family took his passport from him after he was sent back from Turkey the second time, he said he planned to commit an attack in Sweden, the court was told.
Haggkvist said several of the man's family members had expressed concerns about his views, and that his mother and an uncle alerted police.
The man's father and mother declined to take the stand on Friday.
Data retrieved from the man's mobile phone also showed he had searched online for information on how to make a bomb.
During questioning, the man said he had bought the cooker for cooking and could not recall why he had downloaded bomb-making manuals.
Experts at the Swedish Defence Research Agency cited by the prosecutor said the device could have been lethal if it had been assembled, but some explosive ingredients were missing.
The design was similar to that used in the 2013 Boston Marathon bombing in which three people were killed.