A 16-year-old Iranian schoolgirl has been hospitalized and left in a coma after falling unconscious on Tehran's underground days ago.

Kurdish-focused rights group Hengaw said on Tuesday that Armita Geravand was assaulted by female officers from the country's morality police after refusing to wear the Islamic headscarf.

Authorities meanwhile claim she fainted due to low blood pressure.

What do we know about the incident?

Geravand was attacked at the Shohada underground station in Tehran on Sunday, Hengaw said, adding that she incurred severe injuries. She was being treated under tight security at Tehran's Fajr hospital, the group added.

"There are currently no visits allowed for the victim, not even from her family," it said.

Hengaw said the teenager hails from the Kurdish-populated city of Kermanshah in western Iran. She does however live in Tehran.

A female local journalist who tried to visit the hospital, Maryam Lotfi, was briefly detained, Hengaw added.

Iranian authorities deny attack

Meanwhile, Masood Dorosti, managing director of the Tehran underground system, denied in comments to state news agency IRNA "any verbal or physical conflict" between Geravand and "passengers or metro executives."

He referred to CCTV footage which he said refuted the "claim" that the girl was attacked.

The incident comes just over a year after the death of 22-year-old Jina Mahsa Amini, also a Kurd, while in morality police custody.

Amini's death sparked massive, nationwide protests, which were seen as the most serious challenge to the rule of Iran's Islamic leaders since the overthrow of the monarchy in 1979.

rmt/jsi (AFP, dpa)