Before sunrise, thousands of Palestinians streamed towards the mosque in Nablus's Victory Square, swelling the usual crowds of morning worshippers to launch a new front in their protests against Israel and the United States.
The scene has been repeated elsewhere in the West Bank, where people have begun turning out for early prayers in unprecedented numbers, forsaking the usual protest sites where they risk arrest and channelling their anger into a mass expressions of faith.
"This is the most peaceful way to get the message out," said restaurant owner Saif Abu Baker, as the Nablus crowds spilled out of the mosque into surrounding alleyways and courtyards.
Political slogans including "For the sake of God, we have risen up" echoed through Nablus's Old City after the calls from the muezzin and the murmured recitations of the faithful.
"I would hope that it is a new form of channelling the way the message is being sent out there," said Abu Baker. "Because we have tried protesting and it did not work because we don't have enough power. It's the safer way for everyone."
Much of the crowd's message at Friday's fajr (dawn) prayers - the day when most people turn out - was a rejection of the perceived pro-Israel bias of US President Donald Trump's Middle East peace plan.
There have only been small regular street rallies since that plan was launched last week. Few have responded to calls by President Mahmoud Abbas's Palestinian Authority for 'Days of Rage'.
Instead many have begun heeding calls on Facebook and other social media sites to attend what is becoming known as the 'Great Fajr Campaign' - described as a show of solidarity against Trump and what they see as Israeli threats to Islamic holy sites in Jerusalem and Hebron. Those two cities have also seen larger turnouts in the past few weeks.
The first calls for a surge in attendance were from Fatah, Abbas's nationalist political faction that dominates the Palestine Liberation Organisation.
Numbers grew after the campaign gained support from the Islamist group Hamas, which holds sway in mosques, especially in cities where it has a sizeable following.
KNIGHTS OF THE DAWN
Hamas spokesman Fawzi Barhoum, in Gaza, told Reuters the campaign was a bid to alert Palestinians to the Trump plan, and to Israel's plans to annex its West Bank settlements.
In Nablus - where crowds surged to several thousand on Friday, from around 2,000 the week before - worshippers insisted there was no single group behind the drive, describing it as a grassroots movement still finding its feet.
But the streets echoed with chants popular at Hamas rallies, including: "A nation with the leadership of Muhammad will not be defeated".
The event appeared to be organised - extra prayer carpets were rolled out, food and water were available in abundance and the gathering was supervised by stewards wearing fluorescent jackets proclaiming them 'Knights of the Dawn,' and bearing the stencilled image of the nearby al-Nasr (Victory) mosque.
The crowds have been much smaller than the numbers that attended the Great March of Return protests at the Gaza border fence when that campaign started nearly two years ago.
In those Gaza demonstrations, 215 Palestinians were killed and several thousand injured in confrontations with Israeli troops. One Israeli soldier was killed by a Palestinian sniper.
In Nablus the crowds at dawn prayers have been peaceful, with little sign of any heightened security.
Hani Al-Masri, a Palestinian political analyst, said the campaign reflected Hamas's cautious approach to operating in the West Bank, where, unlike Gaza, it faces Israeli troops and Palestinian Authority forces intent on stopping Hamas from inflaming the streets and seizing control.
"Hamas's organisation in the West Bank is not in good shape because of crackdowns by the Palestinian Authority and by Israel," he said.
"Fajr prayers is the most that Hamas can do."
Asked whether Israel was aware of the enlarged dawn prayer meetings, an Israeli military spokesman and the Shin Bet domestic intelligence agency had no immediate comment.