Almost as soon as Philippine President Rodrigo Duterte declared martial law across the war-torn southern island group of Mindanao late on Tuesday , Davao City went into lockdown.

No one was allowed to leave or enter the city, checkpoints were set up everywhere, and plans were drawn up to suspend certain civil liberties, impose curfew and crack down on suspected terrorist cells.

Davaoenos, as residents call themselves, woke up to a city in transition yesterday. Life so far in Davao is carrying on as usual, though there are signs of both resolve and unease.

"We are not bothered. Those who are not from Davao, they may be bothered. But for us who are living here in Davao, we are used to this. We have learnt to live with discipline," said Mr Dahn Espina, 23, a hotel staff member.

Indeed, Davao is no stranger to stern rule.

Mr Duterte, 72, was mayor of Davao for over 30 years. He steered the city to prosperity, but often with a steely focus on discipline. He came down hard on crime and vice, with strict measures like a ban on public smoking and serving alcohol past midnight.

His 38-year-old daughter, Ms Sara Duterte-Carpio, is continuing that tradition as Davao's current mayor.

She virtually quarantined Davao in yesterday's wee hours after her father declared in Moscow that he was placing the whole of Mindanao, including Davao, under martial rule. "We are preventing violence from erupting inside the city. We are preventing violence from entering Davao City," Ms Duterte-Carpio told reporters.

She later downshifted her security posture from a "lockdown" to "hold and secure". That still meant security precautions everywhere, as thousands of police and baton-wielding auxiliary units were deployed across Davao.

Long lines of cars could be seen at the parking entrances of shopping malls. "We've been on red alert since we assumed our duties. That means we have to be be especially vigilant when checking vehicles and cars entering our premises," said Mr Florante Gorgonio, 26, a handler of police dogs at an upscale mall here.

Mr Alrico Bernido, 44, a taxi driver, said he came across four checkpoints late on Tuesday evening and early yesterday morning.

Ms Duterte-Carpio said the precautions are necessary as she has received reports that there are militants identified with the Maute group, which launched attacks in Marawi City on Tuesday.

If needed, she said she was ready to have these suspects arrested without warrants, and impose a curfew across the city.

Raul Dancel