Singer R. Kelly was charged Thursday with 11 new counts of sexual assault and sex abuse, court documents show.

Four of the charges are aggravated criminal sexual assault, two are criminal sexual assault by force, three are aggravated criminal sexual abuse of a victim between 13 and 16 years old and two are aggravated criminal sexual abuse.

The aggravated criminal sexual assault chargesare Class X felonies, which according to NBC Chicago is the most serious felony in Illinois and carries a mandatory minimum prison sentence of six to 30 years.

"These 'new' charges are not really new — they are the same conduct, just charged differently. Same alleged victim, same time frame, same facts," the singer's attorney, Steven Greenberg, said. "And we still expect the same results."

"With the latest charges brought against Robert Kelly, he still maintains his innocence and denies all accusations brought against him," said Darrell Johnson, a representative for Kelly. "He looks forward to a swift and speedy trial."

Kelly, 52, whose real name is Robert Sylvester Kelly, was charged in February with 10 counts of felony aggravated sexual abuse. He has denied all the accusations against him.

"I didn't do this stuff," he told CBS News' Gayle King in an emotional interview in March. "This is not me. I'm fighting for my f---ing life."

The singer pleaded not guilty to the charges in February after posting bond and being released from the Cook County Jail.

According to an unsealed indictment released at the time he was first charged, four people alleged that they were victimized by Kelly. They were only identified in court documents by their initials.

Allegations of sexual misconduct against Kelly gained renewed interest following the January release of the six-part Lifetime docuseries "Surviving R. Kelly," which detailed a number of women's claims that they were sexually, physically and mentally abused by him. He denied all those accusations.

Fallout from the series was swift with Sony Music announcing that it was parting ways with the Grammy-winning singer.

Prosecutors said the alleged sex acts in the original charges occurred between May 1998 and January 2010. Authorities said three of the victims were under the age of 17.

Kelly, who was previously charged with child pornography and was eventually cleared by a jury in 2008 on all counts, told King that the person the women described in the Lifetime series was "Lucifer."

"I'm not Lucifer. I'm a man. I make mistakes, but I'm not a devil, and by no means am I a monster," he said.