MSCaptcha is not shown with url routing asp.net

I am using MSCaptcha in my asp.net web application. I have added required references as well and in web.config I have:

<httpHandlers>
<add verb="GET" path="CaptchaImage.axd" type="MSCaptcha.CaptchaImageHandler, MSCaptcha"/>
</httpHandlers>

I added this to aspx page

<cc:CaptchaControl ID="Captcha" runat="server" CaptchaBackgroundNoise="none" CaptchaLength="6"
CaptchaHeight="50" CaptchaWidth="200" CaptchaLineNoise="Medium" CaptchaMinTimeout="5"
CaptchaMaxTimeout="240" />

when I run the asp.net page, captcha is shown. I have implemented URL routing in asp.net webform using:

routes.Ignore("{resource}.axd/{*pathInfo}");
routes.MapPageRoute("City1Route", "vacancies/All" , "~/City1.aspx");
routes.MapPageRoute("City2Route", "vacancies/City2", "~/City2.aspx");

so when i browse vacancies/all or vacancies/city2 , city1.aspx or city2.aspx are opened but captcha is not loaded even I ignored the route.

Please suggest me how to fix this.