The fire broke out on Tuesday at about 6:30 a.m. local time, as the vessel was on its way back from a two-day cruise. No immediate information on the cause of the blaze was available. According to a report in Tuoi Tre newspaper, all tourist boats in the bay are now to undergo safety checks.

Ha Long Bay, with nearly 2000 limestone islets, is a UNESCO World Heritage Site, and it attracts more than three million tourists a year. There have already been several problems with the cruise boats that ply their trade there. In May last year, 36 tourists managed to escape a burning wooden cruise boat by jumping overboard. When another boat sank in 2011, a total of twelve people died. 

Ha Long Bay has 202 tourist boats that drop anchor on the bay overnight, according to a report from Thanh Nien newspaper in 2016. 

Last year local Communist Party officials in Quang Ninh province said, that only daytime cruises will be permitted in the future, without specifying as of when. "At the moment, overnight cruising in Ha Long Bay is still normal, but in the future, we will not allow overnight cruising in the bay to guarantee safety for tourists," Pham Hong Ha, chairman of Ha Long City People's Committee, said in 2016. 

isi/ks/ms (dpa)