The crackdown on the protests across Iran has resulted in at least 6,159 people being killed, an activist group said.

According to US-based Human Rights Activists News Agency (HRANA), many others are feared dead as the demonstrations against the regime continue.

The group verifies deaths with activists on the ground in the country, with the internet in Iran being cut off by the authorities for a third week.

Out of the 6,159 victims, 5,804 are protesters, 214 security forces, 92 children and 49 civilians uninvolved with the protests. In addition to the number of deaths, HRANA also said 42,200 people have so far been arrested by Tehran.

HRANA's figures have been found accurate in previous rounds of protests in Iran.

The official death toll provided by Iran stands at 3,117, far lower than the number of victims named by HRANA. The Islamic Republic said 2,427 of those killed were civilians and security forces, with the rest being "terrorists."

Tehran has a history of underreporting deaths during unrest and protests.

Aircraft carriers arrives in region

The latest death count comes a day after a group of US aircraft carriers reached the region, giving Washington and its allies a wider array of potential military response to the crisis.

The arrival of USS Abraham Lincoln aircraft carrier, accompanied by guided missile destroyers, means that the US could strike in Iran without having to depart from its bases in the Gulf, after the region's countries voiced their willingness to stay out of any attacks.

The US also announced an Air Force exercise in the Middle East, which will take several days and will "demonstrate the ability to deploy, disperse and sustain combat airpower" across the region, US Air Force component of Central Command said in a statement.

The US military did not make the exercise's date or location known.

Iran braces for possible attacks, warns neighboring countries

Mohammad Akbarzadeh, a representative of the Iran's Islamic Revolutionary Guard Corps' naval forces, was quoted by the state-run Fars news agency that any strikes to be launched from the territories of Tehran's neighboring countries will result in them becoming "hostile."

"Neighboring countries are our friends, but if their soil, sky or waters are used against Iran, they will be considered hostile," Akbarzadeh said.

Two of the region's Iran-affiliated militias said they intend to support Tehran should it be attacked.

Yemen's Houthirebels said any strikes in Iran would result in those attacking tasting "the bitterest forms of death", while Sheikh Naim Kassen, the leader of Lebanon-based militant group Hezbollah, said the organization is ready for "possible aggression" and is "determined" to defend against it.

Edited by: Darko Janjevic