Soldiers have been on patrol on the streets of capital Dhaka, the centre of the demonstrations that spiralled into clashes between protesters and security forces.
Internet and text message services in Bangladesh have been suspended since Thursday, cutting the nation off as police cracked down on protesters who defied a ban on public gatherings.
A curfew ordered late on Friday has been extended to 3pm local time (7pm AEST) on Sunday, until after the Supreme Court hearing, and will continue for an "uncertain time" following a two-hour break for people to gather supplies, local media reported.
Universities and colleges have also been closed since Wednesday.
Nationwide unrest broke out following student anger against quotas for government jobs that included reserving 30 per cent for the families of those who fought for independence from Pakistan.
Prime Minister Sheikh Hasina's government had scrapped the quota system in 2018, but a court reinstated it in June.
The Supreme Court suspended the decision after a government appeal and will hear the case on Sunday after agreeing to bring forward a hearing scheduled for August 7.
The demonstrations, the biggest since Hasina was re-elected for a fourth successive term in 2024, have also been fuelled by high unemployment among young people, who make up nearly a fifth of the population.
The US State Department on Saturday raised its travel advisory for Bangladesh to level four, urging American citizens not to travel to the South Asian country.
