Washington (AFP) -

The United States on Wednesday called on its citizens to avoid all unnecessary travel to Honduras, which is in the throes of a crisis sparked by claims of vote rigging in its presidential election.

In a travel alert, the State Department urged Americans to "postpone or cancel" their travel plans over ongoing protests linked to the disputed November 26 election, which so far has no declared winner.

"Though current demonstrations have largely remained peaceful, demonstrations can be volatile and dangerous, and have included rock throwing, assaults, and tire burning," the State Department said in a statement.

"Moreover, rioting and looting have occurred in many cities throughout Honduras," it added, though noting that the country's Bay Islands are largely unaffected.

Honduras, a small Central American nation of 10 million people, has been plunged into uncertainty since the election pitting incumbent President Juan Orlando Hernandez against leftwing former TV presenter Salvador Nasralla.

Both sides have claimed victory, and election authorities have not declared a winner.

The travel alert is in effect until December 31.