ISLAMABAD, Pakistan — Qandeel Baloch, a Pakistani social media sensation, was strangled by her brother in central Pakistan, police officials said Saturday, in what appears to have been a so-called honor killing.

The police said Ms. Baloch was apparently attacked on Friday night while she was asleep in her parents’ house in Muzaffarabad, a town on the outskirts of Multan in the province of Punjab. Ms. Baloch’s brother, Waseem Ahmed Azeem, was arrested late Saturday night in connection with her death.

Ms. Baloch, 26, a model, singer and social media celebrity, had gained notoriety in Pakistan recently because of provocative, seminude photographs of herself that she posted on social media sites, and appearances in music videos.

Her bold persona defied the conventions of Pakistan, a deeply conservative society. She was reviled by some in the country for being crass and vulgar, and prone to attention-seeking stunts. But other Pakistanis admired her defiance and independence. She attracted more than 700,000 followers on Facebook and at least 40,000 on Twitter.