Senior separatist leader Mirwaiz Umer Farooq on Monday defied house arrest here as he tried to march towards the Army headquarters in the city to protest against civilian killings in Jammu and Kashmir.Authorities had placed Mirwaiz Umer and Syed Ali Geelani under house arrest to foil a planned separatist march to the Badami Bagh Cantonment headquarters.Mirwaiz Umer came out of his house on the city's outskirts Nigeen area along with supporters to take out a march when the police intervened.Mirwaiz Umer said shutting down businesses was the only way left for the Kashmiri people to express their sorrow and outrage over killings of innocents by the security forces who he said had become "a killing machine in Kashmir".Earlier, authorities detained another senior separatist leader, Muhammad Yasin Malik, when he came out with supporters to march towards the Army headquarters in the city.The separatists have called for a protest march to the Army HQ in Srinagar against the killing of seven civilians in Pulwama district on Saturday.Authorities imposed restrictions in Srinagar city blocking all roads leading to the Badami Bagh headquarters to foil the march.