It was learnt that the lit butt had burnt the toilet seat before smoke began emerging from the two-decked vessel.
A passenger, Hamzah Osman, 52, said the incident occurred at 12.35pm after the vessel left the Kuah Jetty here enroute to Kuala Kedah, about 57km away.
"It was just about 20 minutes after we left the jetty when smoke began to billow from the vessel.
"Soon after, the ferry crew told us to wear life jackets as I could see that they were already thinking of a worse-case scenario. Fortunately, they managed to contain the situation," he said.
Hamzah, who was accompanied by his wife, children and grandchildren said the vessel ferried domestic and foreign passengers who were returning to the mainland after spending their holidays at the island here.
The ferry returned to the jetty before the passengers were transferred to another ferry to continue their journey to Kuala Kedah.
![Langkawi ferry](http://img.astroawani.com/2015-02/41424616707_freesize.jpg)
Passengers from Langkawi being transferred onto another ferry to continue their journey to Kuala Kedah on Sunday. - Astro AWANI