The United States has condemned Nigeria's ban on Twitter.

The US Department of State's Spokesman Ned Price said the order had no place in a democracy and contravened freedom of expression.

It was put in place last week after a post by President Muhammadu Buhari was removed.

Despite the suspension, Nigerians have continued to access Twitter using private networks.

The government has vowed to prosecute those violating the ban.

It says its decision to block the site is unrelated to the removal of the president's tweet.

Mr Buhari's post had threatened to punish regional secessionists.