diff --git a/src/lxml/html/clean.py b/src/lxml/html/clean.py

index 6f3f7de..da5af16 100644

--- a/src/lxml/html/clean.py

+++ b/src/lxml/html/clean.py

@@ -73,18 +73,25 @@ _looks_like_tag_content = re.compile(

 # All kinds of schemes besides just javascript: that can cause

 # execution:

-_is_image_dataurl = re.compile(

-    r'^data:image/.+;base64', re.I).search

+_find_image_dataurls = re.compile(

+    r'^data:image/(.+);base64,', re.I).findall

 _is_possibly_malicious_scheme = re.compile(

-    r'(?:javascript|jscript|livescript|vbscript|data|about|mocha):',

-    re.I).search

+    r'(javascript|jscript|livescript|vbscript|data|about|mocha):',

+    re.I).findall

+# SVG images can contain script content

+_is_unsafe_image_type = re.compile(r"(xml|svg)", re.I).findall

+

 def _is_javascript_scheme(s):

-    if _is_image_dataurl(s):

-        return None

-    return _is_possibly_malicious_scheme(s)

+    is_image_url = False

+    for image_type in _find_image_dataurls(s):

+        is_image_url = True

+        if _is_unsafe_image_type(image_type):

+            return True

+    if is_image_url:

+        return False

+    return bool(_is_possibly_malicious_scheme(s))

 _substitute_whitespace = re.compile(r'[\s\x00-\x08\x0B\x0C\x0E-\x19]+').sub

-# FIXME: should data: be blocked?

 # FIXME: check against: http://msdn2.microsoft.com/en-us/library/ms537512.aspx

 _conditional_comment_re = re.compile(

@@ -512,6 +519,8 @@ class Cleaner(object):

             return True

         if 'expression(' in style:

             return True

+        if '@import' in style:

+            return True

         if '

             # e.g. '">'

             return True

diff --git a/src/lxml/html/tests/test_clean.py b/src/lxml/html/tests/test_clean.py

index e40cdad..ad9a598 100644

--- a/src/lxml/html/tests/test_clean.py

+++ b/src/lxml/html/tests/test_clean.py

@@ -1,3 +1,5 @@

+import base64

+import gzip

 import unittest, sys

 from lxml.tests.common_imports import make_doctest

 from lxml.etree import LIBXML_VERSION

@@ -89,6 +91,69 @@ class CleanerTest(unittest.TestCase):

             b'<math><style>/* deleted */</style></math>',

             lxml.html.tostring(clean_html(s)))

+    def test_sneaky_import_in_style(self):

+        # Prevent "@@importimport" -> "@import" replacement.

+        style_codes = [

+            "@@importimport(extstyle.css)",

+            "@ @  import import(extstyle.css)",

+            "@ @ importimport(extstyle.css)",

+            "@@  import import(extstyle.css)",

+            "@ @import import(extstyle.css)",

+            "@@importimport()",

+        ]

+        for style_code in style_codes:

+            html = '<style>%s</style>' % style_code

+            s = lxml.html.fragment_fromstring(html)

+

+            cleaned = lxml.html.tostring(clean_html(s))

+            self.assertEqual(

+                b'<style>/* deleted */</style>',

+                cleaned,

+                "%s  ->  %s" % (style_code, cleaned))

+

+    def test_svg_data_links(self):

+        # Remove SVG images with potentially insecure content.

+        svg = b'<svg onload="alert(123)" />'

+        svgz = gzip.compress(svg)

+        svg_b64 = base64.b64encode(svg).decode('ASCII')

+        svgz_b64 = base64.b64encode(svgz).decode('ASCII')

+        urls = [

+            "data:image/svg+xml;base64," + svg_b64,

+            "data:image/svg+xml-compressed;base64," + svgz_b64,

+        ]

+        for url in urls:

+            html = '' % url

+            s = lxml.html.fragment_fromstring(html)

+

+            cleaned = lxml.html.tostring(clean_html(s))

+            self.assertEqual(

+                b'',

+                cleaned,

+                "%s  ->  %s" % (url, cleaned))

+

+    def test_image_data_links(self):

+        data = b'123'

+        data_b64 = base64.b64encode(data).decode('ASCII')

+        urls = [

+            "data:image/jpeg;base64," + data_b64,

+            "data:image/apng;base64," + data_b64,

+            "data:image/png;base64," + data_b64,

+            "data:image/gif;base64," + data_b64,

+            "data:image/webp;base64," + data_b64,

+            "data:image/bmp;base64," + data_b64,

+            "data:image/tiff;base64," + data_b64,

+            "data:image/x-icon;base64," + data_b64,

+        ]

+        for url in urls:

+            html = '' % url

+            s = lxml.html.fragment_fromstring(html)

+

+            cleaned = lxml.html.tostring(clean_html(s))

+            self.assertEqual(

+                html.encode("UTF-8"),

+                cleaned,

+                "%s  ->  %s" % (url, cleaned))

+

     def test_formaction_attribute_in_button_input(self):

         # The formaction attribute overrides the form's action and should be

         # treated as a malicious link attribute