diff --git a/app/assets/javascripts/components/components/status_content.jsx b/app/assets/javascripts/components/components/status_content.jsx
index 285945fa8..99d83b609 100644
--- a/app/assets/javascripts/components/components/status_content.jsx
+++ b/app/assets/javascripts/components/components/status_content.jsx
@@ -26,7 +26,7 @@ const StatusContent = React.createClass({
       } else {
         link.setAttribute('target', '_blank');
         link.setAttribute('rel', 'noopener');
-        link.addEventListener('click', this.onNormalClick);
+        link.addEventListener('click', this.onNormalClick.bind(this));
       }
     }
   },
@@ -36,7 +36,7 @@ const StatusContent = React.createClass({
       e.preventDefault();
       this.context.router.push(`/accounts/${mention.get('id')}`);
     }
-    
+
     e.stopPropagation();
   },
 
diff --git a/app/assets/javascripts/components/containers/mastodon.jsx b/app/assets/javascripts/components/containers/mastodon.jsx
index 5f691b4bc..220ddc54d 100644
--- a/app/assets/javascripts/components/containers/mastodon.jsx
+++ b/app/assets/javascripts/components/containers/mastodon.jsx
@@ -40,11 +40,15 @@ const Mastodon = React.createClass({
 
     if (typeof App !== 'undefined') {
       App.timeline = App.cable.subscriptions.create("TimelineChannel", {
-        connected: function() {},
+        connected () {
 
-        disconnected: function() {},
+        },
 
-        received: function(data) {
+        disconnected () {
+
+        },
+
+        received (data) {
           switch(data.type) {
             case 'update':
               return store.dispatch(updateTimeline(data.timeline, JSON.parse(data.message)));
@@ -53,6 +57,8 @@ const Mastodon = React.createClass({
             case 'merge':
             case 'unmerge':
               return store.dispatch(refreshTimeline('home'));
+            case 'block':
+              return store.dispatch(refreshTimeline('mentions'));
           }
         }
       });
diff --git a/app/controllers/api/v1/accounts_controller.rb b/app/controllers/api/v1/accounts_controller.rb
index 850d00d2e..930f60cc3 100644
--- a/app/controllers/api/v1/accounts_controller.rb
+++ b/app/controllers/api/v1/accounts_controller.rb
@@ -24,13 +24,25 @@ class Api::V1::AccountsController < ApiController
   end
 
   def follow
-    @follow = FollowService.new.call(current_user.account, @account.acct)
+    FollowService.new.call(current_user.account, @account.acct)
+    set_relationship
+    render action: :relationship
+  end
+
+  def block
+    BlockService.new.call(current_user.account, @account)
     set_relationship
     render action: :relationship
   end
 
   def unfollow
-    @unfollow = UnfollowService.new.call(current_user.account, @account)
+    UnfollowService.new.call(current_user.account, @account)
+    set_relationship
+    render action: :relationship
+  end
+
+  def unblock
+    UnblockService.new.call(current_user.account, @account)
     set_relationship
     render action: :relationship
   end
diff --git a/app/services/block_service.rb b/app/services/block_service.rb
new file mode 100644
index 000000000..6c841d25b
--- /dev/null
+++ b/app/services/block_service.rb
@@ -0,0 +1,25 @@
+class BlockService < BaseService
+  def call(account, target_account)
+    return if account.id == target_account.id
+
+    UnfollowService.new.call(account, target_account) if account.following?(target_account)
+    account.block!(target_account)
+    clear_mentions(account, target_account)
+  end
+
+  private
+
+  def clear_mentions(account, target_account)
+    timeline_key = FeedManager.instance.key(:mentions, account.id)
+
+    target_account.statuses.select('id').find_each do |status|
+      redis.zrem(timeline_key, status.id)
+    end
+
+    FeedManager.instance.broadcast(account.id, type: 'block', id: target_account.id)
+  end
+
+  def redis
+    $redis
+  end
+end
diff --git a/app/services/unblock_service.rb b/app/services/unblock_service.rb
new file mode 100644
index 000000000..d24161423
--- /dev/null
+++ b/app/services/unblock_service.rb
@@ -0,0 +1,5 @@
+class UnblockService < BaseService
+  def call(account, target_account)
+    account.unblock!(target_account) if account.blocking?(target_account)
+  end
+end
diff --git a/app/services/unfollow_service.rb b/app/services/unfollow_service.rb
index feaf28ceb..d22451a74 100644
--- a/app/services/unfollow_service.rb
+++ b/app/services/unfollow_service.rb
@@ -13,7 +13,7 @@ class UnfollowService < BaseService
   def unmerge_from_timeline(from_account, into_account)
     timeline_key = FeedManager.instance.key(:home, into_account.id)
 
-    from_account.statuses.find_each do |status|
+    from_account.statuses.select('id').find_each do |status|
       redis.zrem(timeline_key, status.id)
     end
 
diff --git a/config/routes.rb b/config/routes.rb
index ec151137e..4a32cdaa2 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -74,6 +74,8 @@ Rails.application.routes.draw do
 
           post :follow
           post :unfollow
+          post :block
+          post :unblock
         end
       end
     end
diff --git a/spec/controllers/api/v1/accounts_controller_spec.rb b/spec/controllers/api/v1/accounts_controller_spec.rb
index 7a67f1c56..e4532305b 100644
--- a/spec/controllers/api/v1/accounts_controller_spec.rb
+++ b/spec/controllers/api/v1/accounts_controller_spec.rb
@@ -79,6 +79,44 @@ RSpec.describe Api::V1::AccountsController, type: :controller do
     end
   end
 
+  describe 'POST #block' do
+    let(:other_account) { Fabricate(:user, email: 'bob@example.com', account: Fabricate(:account, username: 'bob')).account }
+
+    before do
+      user.account.follow!(other_account)
+      post :block, params: { id: other_account.id }
+    end
+
+    it 'returns http success' do
+      expect(response).to have_http_status(:success)
+    end
+
+    it 'removes the following relation between user and target user' do
+      expect(user.account.following?(other_account)).to be false
+    end
+
+    it 'creates a blocking relation' do
+      expect(user.account.blocking?(other_account)).to be true
+    end
+  end
+
+  describe 'POST #unblock' do
+    let(:other_account) { Fabricate(:user, email: 'bob@example.com', account: Fabricate(:account, username: 'bob')).account }
+
+    before do
+      user.account.block!(other_account)
+      post :unblock, params: { id: other_account.id }
+    end
+
+    it 'returns http success' do
+      expect(response).to have_http_status(:success)
+    end
+
+    it 'removes the blocking relation between user and target user' do
+      expect(user.account.blocking?(other_account)).to be false
+    end
+  end
+
   describe 'GET #relationships' do
     let(:simon) { Fabricate(:user, email: 'simon@example.com', account: Fabricate(:account, username: 'simon')).account }
     let(:lewis) { Fabricate(:user, email: 'lewis@example.com', account: Fabricate(:account, username: 'lewis')).account }
diff --git a/spec/services/block_service_spec.rb b/spec/services/block_service_spec.rb
new file mode 100644
index 000000000..f6f07fa20
--- /dev/null
+++ b/spec/services/block_service_spec.rb
@@ -0,0 +1,5 @@
+require 'rails_helper'
+
+RSpec.describe BlockService do
+  subject { BlockService.new }
+end
diff --git a/spec/services/unblock_service_spec.rb b/spec/services/unblock_service_spec.rb
new file mode 100644
index 000000000..126f70ff1
--- /dev/null
+++ b/spec/services/unblock_service_spec.rb
@@ -0,0 +1,5 @@
+require 'rails_helper'
+
+RSpec.describe UnblockService do
+  subject { UnblockService.new }
+end