With images of violence and torture coming out of Syria daily, a U.N. panel on Friday stated what many people consider obvious: ISIS has committed war crimes and crimes against humanity, and leaders of the militant group should be held accountable by organizations such as the International Criminal Court.

The U.N. Independent International Commission of Inquiry on Syria based its conclusions on more than 300 firsthand accounts and included photos and videos of violence and victims, a statement said.

"Those that fled consistently described being subjected to acts that (terrorize) and aim to silence the population," said Paulo Pinheiro, chairman of the commission.

The commission issued a paper titled "Rule of Terror: Living Under ISIS in Syria" that described previously known ISIS tactics such as killing, enslavement, rape and sexual slavery. But the report provides details about other, less sensational abuses, such as the penalty for smoking or having tattoos.

"ISIS also carries out amputations and lashings in public spaces in its areas of control," the paper said.

Men have had their hands amputated for allegedly committing theft. The group has also amputated the fingers of men caught smoking, according to the commission's report.

"Men have been lashed for being in the company of women who ISIS considers to be 'improperly' dressed, for smoking, not attending Friday prayers, trading during prayer times and for having tattoos."

(CNN)