Pro-Palestinian protesters interrupted the final stage of the Spanish Vuelta cycling race on Sunday.
There were clashes between police and protesters near the end of the route in Madrid.
Some protesters carrying anti-Israel banners partially blocked the road and forced cyclists to stop.
Riders got off their bikes but race officials have not yet officially called an end to the stage and overall race.
There were about 50 kilometers (31 miles) left on the final stage which appears unlikely to resume.
The protesters threw barriers onto the road on a finishing circuit in the Spanish capital. Riders had been expected to do nine laps on the circuit.
Several hundred protesters stayed on the road where the race was supposed to pass by.
More than 1,500 police officers have been deployed ahead of the final stage of the three-week cycling race.
The Grand Tour event became a diplomatic battleground and was largely disrupted by protesters against the presence of the Israeli-owned Premier Tech team, which earlier in the race removed its name from its uniforms.