git push hangs when using SSH key with a git url

I created a bitbucket account today morning and was successfully able to create and push repositories using a git url and an ssh key.

Now, at night, I'm trying to push a commit, but it just hangs. Here's the debug output:

git push --verbose
Pushing to git@bitbucket.org:xxxx/xxx.git
<hang>

ssh -T is also hanging (worked in the morning)

ssh -T git@bitbucket.org -v
OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to bitbucket.org [131.103.20.167] port 22.
<hang>