Four devices were sent to Mr Lennon, his lawyer Paul McBride QC and former MSP Trish Godman Two men have been detained by police investigating parcel bombs sent to Celtic manager Neil Lennon.
Strathclyde Police said raids were taking place in the town of Kilwinning in Ayrshire, where one suspect package was discovered in a postbox.
Devices were also sent to two prominent Celtic supporters, as well as a Republican supporters group.
The men, aged 41 and 43, were held under the explosive substances act after raids on Thursday morning.
Four devices, which had been sent to Mr Lennon, his lawyer Paul McBride QC and former MSP Trish Godman, were discovered in March and April
Another was sent to Glasgow-based Irish republican group Cairde Na h’Éireann.
Strathclyde Police said their operation in Kilwinning began at 0600 BST, when officers armed with warrants entered a number of properties.
Ch Supt Ruaraidh Nicolson said: “I would expect that there will continue to be a fair amount of activity in this area throughout the day.
“I appreciate that this may be inconvenient to people who want to go about their daily business.
Devices were sent to Neil Lennon (L), Trish Godman and Paul McBride QC “I can assure you that we will be doing everything we can to keep disruption to a minimum and to get the local area back to normal as quickly as possible.
“I would say, though, that if anyone has any concerns, please speak to one of the officers at the scene or call your local police station.”
The raids come the morning after a man was detained in connection with an attempted assault on Neil Lennon on the pitch at Tynecastle, in the game between Hearts and Celtic.
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