Efforts to restore Derry services after security alerts disorder
Transport, postal and social housing services have been affected following Monday's disorder, which led to hundreds being evacuated from their homes and bomb disposal experts carrying out checks.
Three vehicles were hijacked in separate security alerts, including two hijacked at gunpoint.
The alerts ratcheted up tensions already running high following Saturday's car bombing which has been blamed on dissident republican group the New IRA.
Five people arrested over the bombing – aged 50, 42, 34 and two aged 21 – have since been released unconditionally.
Police believe Monday's security alerts were designed to "frustrate" their investigation into Saturday's attack.
The Housing Executive yesterday said maintenance and heating contractors have been withdrawn from some areas of Derry after a contractors' van was hijacked.
It apologised to tenants but said the "protection and safety of people who work for us is paramount" and "given the circumstances, this decision is unavoidable".
"We hope that there is a resolution to enable services to resume as soon as possible," the public housing body said.
Royal Mail said that following advice from the PSNI, its workers would not be attending certain areas of the city after a hijacking of one of its vans.
Sinn Féin Foyle MP Elisha McCallion said transport facilities were among the services impacted by the disorder.
She called for an urgent meeting with statutory agencies aimed at restoring affected services.
"I have asked the Unity of Purpose group to urgently convene a meeting with the key statutory agencies that have had services affected as a result of this mindless spate of alerts," she said.
"It's important that we do that in order to demonstrate that the political and civil leadership of this city is absolutely united in its opposition to what we have witnessed over the past number of days."
The PSNI said its main line of inquiry is that Saturday's bomb and Monday's alerts were orchestrated by the New IRA.
In the first of Monday's incidents, three men reportedly hijacked a white Transit van in the Circular Road area at around 11.30am before throwing an object in the back and abandoning the vehicle.
At 1.45pm, police received a report that four masked men – one allegedly armed with a gun – had hijacked a postal delivery van on Southway.
Both incidents prompted sizeable security alerts, with nearby residents evacuated.
In the third incident, an Asda delivery van was left parked across Northland Road, stopping traffic in front of St Mary's secondary school.
Derry's top police officer Gordon McCalmont condemned those involved in sparking the security alerts.
"Two out of the three – there has been mention of guns being involved," he said.
"Those drivers were going out to their work yesterday, going to do a day's work and support their families, and I'm sure not for one minute did they think they would be confronted by armed masked men.
"It's madness, that is the reality of it."
Mr McCalmont said he believed Monday's alerts were aimed at impeding the investigation into Saturday evening's car bomb attack in Bishop Street.
He added: "The support we have had has been absolutely fantastic, we've had residents thanking ATO and officers when being evacuated from their homes – we're working hard as a community, political, church and otherwise.
"I'd like to repeat that Derry is very much open for business today."
Mr McCalmont also rejected criticism that the PSNI rushed into the arrests in order to calm a worried public.
"Everything we have to do is lawful and necessary – that criticism is unwarranted," he said..
No new checkpoints will be set up in the city as the PSNI does not want to add to the disruption already caused.
DUP Policing Board members George Dorrian and Mervyn Storey were among a delegation that met with PSNI chief constable George Hamilton yesterday morning.
Mr Storey voiced confidence in police to deal with the security situation.
"Let's remember, police and the security services have been able to thwart other incidents in the past and I think that is something as a community in Northern Ireland we ought to be very thankful for," he said.