"There have been no specific intelligence inputs or any official alerts, but going by media reports we have stepped up security at the Taj," senior police superintendent Preetender Singh told AFP on Friday.
"Security drills are being carried out on a six-hourly basis instead of the usual daily drill."
Members of the bomb disposal squad and Special Weapons and Tactics (SWAT) team have been deployed with additional personnel patrolling the Yamuna river which flows next to the Taj, he said.
India's leaders say the IS group does not have influence in the country of over 1.2 billion people, which has a large but traditionally moderate Muslim population.
There have been some reports of Indians going to fight for the group in Iraq and Syria, but the numbers are low relative to the size of the population.
Last week, police said an IS sympathiser accused in a train explosion that injured 10 people had been killed in a stand-off as they tried to arrest him.
Singh said the nature of any threat remained unclear but police did not want to leave anything to chance.
"Based on the inputs so far, we have beefed up the security and are fully prepared to handle any eventuality," he said.
"The Taj is in safe hands."