Three Italian nationals were detained on Thursday after 24 live cartridges were recovered from their room in south Delhi's Radisson hotel, police said.
The housekeeping staff of the five-star hotel found the cartridges while cleaning room number 448 Thursday morning. The foreigners had vacated the room on Tuesday, a police officer said.
"The Italian nationals checked in the room Tuesday morning and vacated the room the same day. One of them was detained in Mumbai while the other two where caught in Pune," the officer added.
Security has been beefed up at the hotel, located close to the Indira Gandhi international airport.
In February, two British nationals were caught from the same hotel while they were involved in plane spotting. They were later granted bail and let off.