Industrial action has seriously disrupted operations at Egypt's Ain Sokha port, run by DP World, a union representative and the operator said on Saturday.
Angered at the dismissal of eight of their colleagues, port workers started their action three days ago with a partial strike which turned into a full strike on Saturday, said Ashraf Eissa, the union representative.
"Loading and unloading in the port are at a total standstill," he said.
The workers want their sacked colleagues reinstated.
In a statement, DP World in Dubai said: "Labour issues have caused a significant slowdown in operations, impacting both customers and the Egyptian economy. We are working to resolve the issues appropriately as soon as possible."
Ain Sokhna, near the southern end of the Suez Canal, is Cairo's main port for cargo from the Far East.
DP World temporarily shut down the Ain Sokhna port in February during a five-day stike by workers demanding profit shares and risk allowances.
Several hundred employees staged another partial strike in late June, saying that management promises had still not been fulfilled.
DP World is the third largest port operator in the world.