Six people have been wounded in a stabbing at the Gay Pride parade in Jerusalem, according to the city's ambulance service.
Two of those injured are in serious condition, a spokesperson for the service said.
Police spokeswoman Luba Samri said a man had been arrested. He was identified by local media as an ultra-Orthodox Jew.
A similar incident at the 2005 parade saw four marchers stabbed and wounded.
Yishai Schlissel, an ultra-Orthodox Jew, was sentenced to 12 years in prison for the 2005 attack.
The march has long been a source of tension between Jerusalem's secular majority and its Jewish Orthodox communities.
Hundreds of police are deployed along the route to prevent violence breaking out.