Dhaka, Oct. 24 -- US intelligence has warned that Iran has substantially increased efforts to target American diplomats and officials abroad, with some alleged assassination plots reaching advanced stages, Axios reports.

The warning was contained in an unclassified memo dated Oct 23 and sent to Secretary of State Marco Rubio.

According to Axios, the memo said intelligence about the alleged plots needed to be shared with more US personnel than were currently authorised to receive it.

It did not identify specific targets, countries outside West Asia or the nature of the alleged plots.

The intelligence had already been shared with senior State Department officials, and the memo offered to downgrade as much of the sensitive material as po...