Cops shot a man in Far Rockaway after he stabbed his sister Tuesday morning, police sources said.

The incident happened on Shore Front Parkway near Beach 102nd Street around 12pm, according to police.

The man stabbed his sister four times in the chest and still had the knife in his hand when police arrived, the sources said.

Cops ordered him to drop the knife and when he refused, they attempted to tase him, but it was ineffective, said the sources. When he moved toward them, police fired one shot, striking him in the leg.

Both brother and sister were taken to Jamaica hospital in serious condition.