Flights on Zimbabwe's national airline are not yet back to normal, a day after all its seven aircraft were grounded when the airline ran out of fuel.
President Mugabe regularly uses Air Zimbabwe flights
The authorities said services resumed after a shipment of fuel arrived, but some domestic services were still not operating on Tuesday.
A foreign exchange crisis has led to a severe fuel shortage in Zimbabwe.
State media said hundreds of passengers were stranded, and airline officials had been suspended from their jobs.
Air Zimbabwe has suffered cancellations in the past, but Monday was the first time the airline was forced to ground all its planes.
Fuel for motor vehicles has long been in short supply. Motorists have to contend with long fuel queues, and petrol trades on the black market at premium prices.
The state-owned Herald newspaper said Air Zimbabwe's board had suspended chief executive Tendai Mahachi and company secretary Tendai Mujuru "pending investigations into serious disruptions of the national airliner's operations and services".
Air Zimbabwe serves the country's main cities and tourist centres as well as southern African destinations, and long-haul routes to London, China, Singapore and Dubai.
"All planes have been grounded because there is no adequate foreign currency to buy fuel and flights have been suspended until further notice," an Air Zimbabwe official told Reuters news agency on Tuesday morning.
Government critics blame Zimbabwe's foreign exchange shortage on economic mismanagement and the near-collapse of commercial agriculture following a hasty land reform programme.
The government says sanctions are responsible for the country's economic problems.
Air Zimbabwe's fleet includes two MA60 aircraft obtained this year from China as part of President Robert Mugabe's "Look East" policy.
Mr Mugabe has in the past been accused of compounding the airline's problems by commandeering planes for his personal use.