When armed men fired on protesters in the Sudanese capital Khartoum earlier this month, killing six and injuring dozens, witnesses were quick to blame the Rapid Support Forces, a feared paramilitary outfit.

The forces are commanded by Mohamed Hamdan Dagalo, known as Hemedti, who also serves as deputy head of the Transitional Military Council, which has been running Sudan since Omar al-Bashir was ousted by the army after months of protests on 11 April.

Though witnesses saw troops in RSF-marked vehicles opening fire as they cleared barricades, Hemedti said those responsible for the violence had been found inside Khartoum University and the protesters’ encampment.

“These people have been arrested and confessed on camera,” he said, without offering further details or proof.

Bashir’s 30-year rule had been marked by civil war and widespread human rights abuses. The generals who seized power have resisted calls from the demonstrators and the international community to step down, insisting a new governing body be led by an officer.

Sudanese protesters at the sit-in in Khartoum last week. Photograph: Amel Pain/EPA

As talks over the governing body remain deadlocked, Hemedti has increasingly been seen as a key player. His influence was underlined on Friday when it emerged he had met the Saudi crown prince, Mohammed bin Salman, while on a visit to Saudi Arabia. Riyadh has emerged as a key supporter of the new rulers of Sudan since Bashir’s fall.

The RSF has been repeatedly deployed in recent years to crack down on pro-democracy and other protesters. Around 10,000 RSF paramilitaries are deployed or close to Khartoum, observers say.

Hemedti has warned protesters against any further “chaos”, hinting late last month that the military may use force if the unrest continues. But he has also repeatedly said he would like to see democracy in Sudan and he refused orders from Bashir to violently disperse the sit-in outside the military headquarters in the capital that precipitated the dictator’s fall.

Last week, he told Egypt’s state newspaper al-Ahram that the ruling military council “wants to hand over power today not tomorrow”.

Western envoys and opposition activists in Khartoum say Hemedti, who comes from a family of camel traders in a remote province and dropped out of primary school, hopes to become president. “Hemedti planned on becoming the number one man in Sudan. He has unlimited ambition,” said an opposition figure who asked not to be named for fear of reprisals.

Protesters in Khartoum demand the installation of civilian rule. Photograph: Ashraf Shazly/AFP/Getty Images

Analysts say Hemedti is backed by an informal coalition of diverse supporters. Some see him as an ally against the Islamist movement that orchestrated the 1989 coup, which brought Bashir to power and underpinned his regime.

Hemedti also supplied ground forces to the Saudi-led coalition fighting Iran-aligned rebels in Yemen and can count on the support of the Saudis, the United Arab Emirates and Egypt, all of whom hope to sideline the Islamists.

His rise is closely linked to the ongoing conflict in his native Darfur, where his forces are accused of continuing the scorched-earth campaign against rebels that Bashir launched in 2003, and for which the former president was indicted for war crimes and genocide by the international criminal court.

About 300,000 people were killed and 2.7 million were forcibly displaced in the early years of that conflict, when the government-backed Janjaweed militia torched villages and killed and raped ethnic Africans across the Darfur region.

In an interview with documentary filmmakers in 2008, Hemedti said Bashir had personally asked him to lead the campaign against the insurgency in Darfur but he denied any involvement in attacks on civilians and said he had refused orders to attack civilian areas.

Magdi el-Gizouli, a scholar at the Rift Valley Institute, a thinktank focused on East Africa, said Hemedti’s rise was enabled by the Sudanese military’s strategy of outsourcing counter-insurgency operations to local forces.

Protesters at the sit-in in Khartoum. Photograph: Amel Pain/EPA

“In essence, he is the reason why the rebellion in Darfur was defeated, because he was capable of recruiting an efficient fighting force that knew the local terrain well, that knew the geography well, and that had an axe to grind against farming communities in Darfur,” he said.

Sudan’s pro-government militia were eventually reorganised into the RSF in 2013 in an attempt to impose greater discipline and more closely tie them to the armed forces. Under Hemedti’s command, the RSF waged two major counterinsurgency campaigns in Darfur, in 2014 and 2015.

A 2015 report by the New-York-based Human Rights Watch found the RSF had “committed a wide range of horrific abuses”, including forcibly displacing entire communities, destroying wells and plundering livestock. “Among the most egregious abuses against civilians were torture, extrajudicial killings and mass rapes,” it said.

Witnesses to a 2015 attack by the RSF in Darfur’s Jebel Marra region said troops had carried out mass rape in and around the village of Golo, often gang-raping women and girls in front of local elders before killing the women and leaving their bodies in the streets, Human Rights Watch said.

The international criminal court has not brought charges against Hemedti. But it said in a 2014 report the RSF under his command was “similar in structure and modus operandi” to earlier militia, with a “similar pattern of indiscriminate and disproportionate attacks against civilians”.