Dissident republicans blamed for Strand Road, Derry, bombs
Security forces were the target of two bombs left in Londonderry overnight, the police have said.
A pipe bomb and booby trap bomb on a timer were both made safe by the Army.
The pipe bomb was left in a holdall at Derry City Council's office grounds and the booby trap attached to a bicycle chained to railings on a walkway at the back of the offices.
Dissident republicans are being blamed for leaving the bombs which were discovered late on Thursday night.
Police said a Foyle Search and Rescue volunteer who lifted the holdall and looked inside could have been killed.
"I'm under no doubt that the device on the bicycle was intended to kill police officers or the army disposal officer who turned up to deal with the first device," Chief Inspector John Burrows said.
"They were perfectly happy to take the risk that innocent members of the public could be killed.
"A young person could have touched this bicycle and have been killed.
"The volunteer from Foyle search and rescue who found the holdall could have been killed."
A number of houses close to the Strand Road scene were evacuated during the security alert.
All roads in the area have reopened to traffic following the alert but the police operation is continuing.
However, 200 staff at Derry City Council and 100 at Fujitsu, which has offices next door, were told not to come in to work.
The alarm was raised shortly after 23:00 BST on Thursday when a suspicious object was found during a routine patrol by the Foyle Search and Rescue team.
The charity is staffed by volunteers who patrol the River Foyle and its banks in an effort to promote safety on the waterway.
The chairman of Foyle Search and Rescue, Craig Smyth, said a member of his staff found a holdall bag near a fence at the back of the council offices.
"One of the female volunteers opened the bag. It was like a normal rucksack sitting at the side of the river," Mr Smyth said.
"She saw a metal pipe like device inside. "She set down the bag and walked away and knew not to reach into it.
"It was very frightening for her."
"There were three people standing around the bag, all of them could have been killed."
The woman then called the police.
SDLP MLA for Foyle, Mark H Durkan, said the discovery by the search and rescue volunteer "could actually have cost them their lives while they're out trying to save others".
He said PSNI officers had told him that one of the devices was found at the back of the building while the other was discovered within the council office grounds.
A separate alert on Markethill Road in County Armagh has been declared a hoax after the Army carried out a controlled explosion on an suspicious object.
The alert began on Friday morning and the road had been closed between Markethill and Newtownhamilton.