* Media suspensions come amid heightened political tensions
* Newspapers close to former President Laurent Gbagbo
ABIDJAN, Sept 14 (Reuters) - The United Nations and Washington criticised on Friday the suspension of six Ivory Coast newspapers allied to the political party of former President Laurent Gbagbo by the country's media authority.
The national press council suspended the dailies on Wednesday for publishing a photograph of Gbagbo with a government he named in defiance of the international community following his defeat at the polls in 2010.
Gbagbo's refusal to accept President Alassane Ouattara's victory led to a civil war last year, which killed more than 3,000 people.
The media regulator ruled the publication of the picture had sought to "prolong the post-election crisis" by suggesting the existence of a second government in Ivory Coast.
Five of the dailies were banned for six editions and one for 12 editions. While such suspensions are common in the west African nation's heavily politicised media landscape, the latest bans provoked unusually swift and stern international rebukes.
The United States said it was concerned by the decision. "Ivorian people should be allowed to determine for themselves the validity of competing political views, statements and arguments," a statement from the U.S. embassy in Abidjan said.
Opposition politicians have accused the government of using a wave of attacks on military and police installations last month as a pretext for a crackdown on dissent.
The country's U.N. peacekeeping mission said the newspaper suspensions were "a very unhealthy sign".
"In the current context, everyone should focus on looking at ways to move forward on the path of dialogue and reconciliation," spokeswoman Sylvie van den Wildenberg said.
Paris-based Reporters without Borders, an organisation which advocates press freedom, said: "This collective suspension worries us. This decision is a true step back for the freedom of the press in Ivory Coast."
Gbagbo is awaiting trial at the International Criminal Court charged with crimes against humanity committed during last year's war. (Reporting By Joe Bavier; Editing by Bate Felix and Pravin Char)