At least 10 Tajik troops were killed in clashes with militants in the east during a military operation that followed the murder of a top security official, a military source said Tuesday.

Over 20 troops had also been wounded in the clashes, which came after Tajikistan sent special forces into Badakhshan province following the murder of the top regional security official Abdullo Nazarov at the weekend, the source told Agence France Presse, asking not to be named.

Iranian President Mahmoud Ahmadinejad and his Pakistani counterpart Asif Ali Zardari arrived in Tajikistan on Saturday for regional security talks with Afghan leader Hamid Karzai.

The three are due to sit down with their Tajik host Emomali Rahmon on Sunday while a top US official is also due to meet diplomats from Pakistan and Afghanistan to discuss the outcome of Karzai's February visit to Islamabad.

Authorities in Tajikistan on Sunday allowed access to Facebook following an outcry from international organizations over the recent blocking of independent media sites.

"Yes, we've allowed access to Facebook but we don't know how long it will last," said a spokesman for an Internet provider in the Tajik capital Dushanbe.

The Tajikistan government ordered Internet providers on Saturday to block Facebook, along with several independent media sites, a spokeswoman for the country's web-provider association told Agence France Presse.

"Internet providers received a spoken order from government agents to block the sites," said Parvina Ibodova, president of the association.

The United States is trying to increase the flow of non-lethal supplies to U.S. troops in Afghanistan via Uzbekistan as it may not always be able to count on the Pakistan route, a U.S. official said Saturday.

The official spoke as U.S. Secretary of State Hillary Clinton visited Tajikistan and Uzbekistan, part of the U.S. military's Northern Distribution Network (NDN), following a trip to Pakistan to discuss troubled ties there.

Iranian President Mahmoud Ahmadinejad lashed out at global powers Monday for interfering in domestic affairs of Asian and African countries as he unveiled a hydroelectric power station in Tajikistan.

"We are very concerned over interference of superpowers and strangers in the internal affairs and problems of our region and Africa," Ahmadinejad said at the opening ceremony of a hydro-power station built as a joint project with the fellow Persian-speaking country.

A senior Russian officer in President Dmitry Medvedev's security entourage died in the Tajikistan capital Dushanbe ahead of a visit by the Kremlin chief, the Tajik interior ministry said Thursday.

The 38-year-old Vladimir Kuznetsov died of a heart attack in the Dushanbe's Hyatt Regency hotel on Wednesday, the ministry said, adding doctors have ruled out foul play.

The impoverished ex-Soviet republic of Tajikistan on Tuesday unveiled what is being billed as the world's tallest flagpole in a ceremony marking its 20th anniversary of independence.

"A thousand years on, the Tajik people have regained the independence and statehood they had sought all these years," Tajik President Emomali Rahmon said in a grand ceremony broadcast on all four state television channels.

One Tajik policeman was killed and another two received gunshot wounds when they clashed with runaway militants in a remote region near the Afghan border, police said on Tuesday.

Police said the gunmen were part of a group of militants who escaped from a detention center last August, killing six prison guards.