NEW DELHI — An adult Indian elephant that washed up in a swamp in Bangladesh after being caught up in raging floodwaters has become a jumbo problem for wildlife officials on both sides of the border.
Flood waters from monsoon rains carried the male elephant thousands of miles from upstream India before he became trapped in a swamp in Bangladesh’s Jamalpur district some three weeks ago.
Indian wildlife authorities abandoned a plan to send the elephant back to India because he was unlikely to be welcomed by his herd in the hilly forests of the remote northeastern state of Assam. They then agreed to let him be transferred to the park.
Tapan Kumar Dey, a retired forest conservator who was overseeing the rescue efforts, said wildlife workers tranquilized the elephant Sunday to bring him closer to a highway to truck him to a safari park outside Dhaka, Bangladesh’s capital.
Dey said wildlife experts were experimenting with tranquilization dosages because they wanted to make the transfer to the truck go smoothly. The swampy area with the elephant, whose age was not clear, was a few miles from the highway.
Forest guards and wardens also used chains and iron hooks to get the elephant to start moving, Dey said. Wildlife authorities plan to use at least two domesticated elephants to help lead the way.
‘‘We plan to use some elephants to encourage it to walk with them toward the main highway,’’ Dey said.
The elephant appeared to be in good condition, although when forest guards found him, he was dehydrated after being stuck in the swamp for days, Dey said.
Another problem that wildlife wardens were facing was controlling the hundreds of people who have gathered to watch the rescue efforts, Dey said. Local villagers have named the elephant ‘‘Bangabahadur,’’ or ‘‘Hero of Bengal.’’
Security officials had to be deployed Saturday and Sunday to hold back curious villagers and keep them from hooting and cheering, which could disturb the elephant.
Heavy downpours have flooded vast swaths of eastern India since monsoon rains began in June.