"I feel very sad. She did a lot of things for our country," Chotinart Arunlert, a 71-year-old housewife in Bangkok, said. Chotinart said she had been at the hospital since 05:00 local time to pay her respects to the princess.
Surayud Chulanont, the army-installed prime minister, also announced a 15-day nation-wide period. Flags at all public buildings will be flown at half mast during the period.
The interior ministry has also asked entertainment businesses including bars and karaoke lounges to "refrain from entertainment activities" during the period, a government official said without elaborating.
Coalition talks halted
The princess’s death has put a temporary halt to post-election coalition haggling.
Two political parties - Chart Thai and Puea Pandin - have already decided to postpone their announcement on joining a coalition government led by allies of ousted premier Thaksin Shinawatra.
The pro-Thaksin People Power Party won 233 of the 480 parliament seats in the December 23 poll, the first since last year's coup ousting Thaksin.