India, April 24 -- Thousands of Samsung Electronics workers rallied Thursday at its computer chip complex in Pyeongtaek, South Korea, demanding higher bonuses and threatening to strike as booming demand for artificial intelligence drives up memory-chip profits.

Holding signs and waving banners, the workers gathered at a factory compound amid a heavy police presence, shouting "make compensation transparent and remove maximum limits on bonuses!" Union officials said about 40,000 members participated in the protest. Police did not immediately provide a crowd estimate.

The rally came hours after Samsung's cross-town rival, SK Hynix, posted an all-time high in quarterly revenue and operating profit for the January-March quarter, a jump it at...