Stalls in axial gas turbines engines occurs when the angle of attack of the blades exceeds the critical angle of attack, just like a wing. This happens when the axial velocity of the air in the engine is significantly lower that the rpm of the compressor stage.
This can occur in multiple situations:

• Disrupted airflow at the engine intake
• Damaged compressor blades
• Damaged turbine blades
• Engine acceleration/deceleration too rapid

Stalls at low speed usually occur because the acceleration of the engine is exceeding the acceleration at which air can move towards the intake of the engine, causing a stagnation of air at the rear of the compressor stages. In other words, the RPM of the compressor stage will exceed the axial air velocity. Therefore there is a lack of air ahead of the front stage of the compressor, making it stall first. Usually this is followed by a complete compressor stall, and possibly a surge depending on the severity of the stall.

To avoid compressor stalls, Variable Inlet Guide Vanes (VIGV) and Variable Stator Vanes are installed to change the relative flow of the air between the compressor sections, therefore reducing the effective angle of attack of the blades. Also some engine have a bleed in the rear of the compressor section to prevent excessive pressure causing potential back pressure.

The other answers are incorrect:

• “Not tendency to stall”: Compressor blades are built so that they achieve their optimum angle of attack at the aircrafts normal operating speeds, so cruise speeds, for maximum fuel efficiency. Therefore at low aircraft speeds and during engine start when there is little or no axial airflow velocity, the compressor has a high tendency to stall or surge if care isn’t take. Modern FADEC systems combined with the VIGV’s and the VSV’s prevent this from happening therefore it usually isn’t a problem anymore unless a compressor/turbine section is damaged.
• “A tendency to stall in the center stages”: Axial compressor usually stall first in the front stage of the compressor.
• “A tendency to stall in the rear stages”: Axial compressor usually stall first in the front stage of the compressor.