On Saturday a Ukrainian fighter inside said some 20 women and children had made it out.
Muhyiddin said he resigned along with his cabinet after losing majority support in parliament.
The king has the constitutional power to appoint a prime minister from amongst elected lawmakers based on who he thinks can command a majority.
Conventionally, between the dissolution of one Parliament and the convening of the next, the prime minister and the remain in office in a capacity.
It is also unclear that any single lawmaker or party has enough seats to command a parliamentary majority, as Muhyiddin pointed out in a nationally televised speech on Friday.
But elections are unlikely in the short term as Malaysia has seen a record number of COVID infections and deaths in recent days.