Ghaziabad/Delhi, June 7 -- An unidentified caller allegedly issued a death threat to Delhi chief minister Rekha Gupta late on Thursday night, prompting a joint investigation by the Ghaziabad and Delhi police. According to officials, the threat was made around 11pm when the caller dialled the 112 emergency number in Ghaziabad and threatened to kill the Delhi CM before abruptly disconnecting the call. "The caller made a short call saying he would kill the Delhi CM, and then hung up. We informed our counterparts in Delhi and are trying to trace the caller," said Dhawal Jaiswal, deputy commissioner of police (city zone), Ghaziabad. While no FIR has been registered yet, officials said the number used was registered in Uttar Pradesh and the calle...