Please do in this way
mydomain = "ec2-222-333-444-244.us-west-1.compute.amazonaws.com"
q= '{ "script":"ctx._source.id = val", "params":{ "val":11316623} }'
_id = "11316623"
response = RestClient.post "http://#{mydomain}/monitoring/mention_reports/#{_id}/_delete", :q => q, :content_type => :json, :accept => :json
json_res = JSON.parse(response)
it should be
RestClient.post 'http://example.com/resource', :param1 => 'one', :nested => { :param2 => 'two' }
in this format