The Syrian anti-regime alliance that toppled the Bashar Assad regime has continued its momentum to deploy police, install an interim government and meet foreign envoys to assert control in the war-torn country.

Since the regime's removal Sunday, senior bureaucrats of the Hayat Tahrir al-Sham-led (HTS) alliance have moved into government headquarters in Damascus.

The appointment of Mohammed al-Bashir, the head of the regional government in the HTS' enclave of Idlib, as Syria's new interim prime minister on Monday underlined the group's status among groups that battled for more than 13 years to end Assad's dictatorship.

The HTS has reassured tribal leaders, local officials and ordinary Syrians during its march to Damascus that it would protect minority faiths, winning broad approval.

The message helped smooth the opposition's advance and the group's leader Abu Mohammed al-Golani has repeated it since Assad's ouster.

At the office of the Damascus governor, its walls exquisitely decorated with marquetry and stained glass, the man brought from Idlib to run affairs dismissed rumors that Syria would have a religious form of governance.

"There is no such thing as Islamic governance. After all, we are Muslims and it's civil institutions or ministries," said Mohammed Ghazal, a bespectacled 36-year-old civil engineer who was raised in the United Arab Emirates and spoke in near-perfect English.

"We don't have any problem with any ethnicity and religion," he said. "The one who made the problem was the (Assad) regime."

Al-Bashir has said he will only remain in power until March although HTS has yet to spell out key details of the transition process, including its thinking on a new constitution.

Al-Golani, in a statement to Reuters on Wednesday, said he would dissolve the ousted regime's security forces, close its prisons, and hunt down anyone involved in torture or killing detainees.

While Syrians celebrate the fall of Assad's brutal police state, some voiced fears about uncertainties.

Zakaria Malahifji, secretary-general of the Syrian National Movement who once served as political advisor to opposition groups in Aleppo, said the lack of consultation in forming an interim government was a misstep.

"You are bringing (ministers) from one color, there should be participation of others," he said. "Syrian society is diverse in terms of cultures, ethnicities, so frankly this is concerning," he said.

'Ruins, ruins, ruins'

Like other members of the HTS-affiliated Salvation Government in Idlib brought to Damascus to run state bodies, Ghazal said he had given assurances to employees and urged them to return to work. "It's a collapsed state. It's ruins, ruins, ruins," Ghazal said.

His priorities for the next three months are getting basic services running and streamlining the bureaucracy. Salaries, which average some $25 a month, would be increased in line with Salvation Government wages. Its minimum wage is $100 a month.

"Syria is a very rich country," said Ghazal, asked how this would be financed. "The regime used to steal the money."

Policemen brought from Idlib are directing traffic in Damascus, trying to restore some normalcy since the HTS ordered armed groups out of the city. One officer, who did not give his name, said they were stretched thin, noting they previously just had to patrol Idlib.

Though the HTS is pre-eminent among the factions that fought Assad, others remain armed, notably in areas at the borders with Jordan and Türkiye.

During the war, anti-regime factions often clashed with each, leaving a legacy of rivalries and enmity seen as one of many risks to stability in post-Assad Syria.

Yezid Sayigh, a senior fellow at the Carnegie Middle East Center, said the HTS "clearly is seeking to maintain the momentum on all levels," adding that any group in their position, taking over from a collapsed regime in an exhausted country, would behave broadly the same way.

But he assessed the diversity of Syria's opposition and society would make it difficult for one group to monopolize influence.

Türkiye – an influential backer of the opposition – was also keen for a government that could win international backing, he said.

Meanwhile, an opposition source familiar with HTS consultations said all of Syria's sects would have representation in a caretaker government. Issues to be determined in the next three months included whether Syria should have a presidential or parliamentary system of government, the source said.

In an interview with Italian newspaper Il Corriere della Sera published on Wednesday, Prime Minister Bashir said, "We will only stay until March 2025."

The priorities, he said, were restoring security and state authority, bringing home millions of Syrian refugees and providing essential services.

Mohammed Alaa Ghanem, a leading Syrian activist based in Washington and in touch with senior opposition figures, said the HTS was being urged to "be smart and get the transition right, instead of letting the moment go to their heads by completely dominating the new government."

The Biden administration has urged the HTS not to assume automatic leadership of Syria but instead run an inclusive process to form a transitional government, according to two U.S. officials and a congressional aide briefed on the first U.S. contacts with the group.

U.S. Secretary of State Antony Blinken has said the transition in Syria should lead to "credible, inclusive, and non-sectarian governance" consistent with U.N. Security Council Resolution 2254.

That resolution, approved in 2015, calls for a Syrian-led process facilitated by the United Nations, establishing within six months non-sectarian governance and setting a schedule for the process of drafting a new constitution.

It also calls for free and fair elections.