Delhi Chief Minister Arvind Kejriwal on Monday demanded an apex court monitored probe into the killing of eight alleged SIMI activists in a gunfight with police, after they escaped from Bhopal Central Jail."We demand an SC monitored investigation (into the case of killings of SIMI activists)," Kejriwal tweeted.In response to a scribe's tweet which questioned the state version of the encounter, saying it was "Gujarat model being truly replicated elsewhere", Kejriwal said, "It was very serious."Earlier, the Communist Party of India (Marxist) also demanded a judicial probe into the killings.Eight members of the banned Students Islamic Movement of India (SIMI) who escaped from Bhopal Central Jail on Monday were killed in a gunfight on the outskirts of the city, police said.