New sister city for Bangkok

On January 4th, Bangkok governor Sukhumbhand signed a contract with the mayor of the Cambodian capital city Phnom Penh to make the two cities sister cities.

Phnom Penh is the 24th city to team-up with Bangkok. The capital's other twin cities include Washington DC, Beijing, Moscow, St Petersburg, Budapest, Brisbane, Manila, Seoul, Jakarta, Vientiane, Tehran and Shanghai.
The Nation, Phnom Penh, Bangkok now twin cities, 2012-01-05

When I last wrote about the sister cities of Bangkok, the Wikipedia article had totally bogus entries, and there was only a outdated list on the website of the city administration listing just 14 sister cities. When rechecking now, Wikipedia had the list of 22 sister cities same as the website of Bangkok - and someone already added Phnom Penh as well. Since The Nation had a partial list in their article as quoted above, it seems the missing city is Tehran, the capital of Iran. I wasn't able to find any other reference confirming that relationship, and have become somewhat skeptical in believing that newspaper.