The force said that in areas of both Blackburn and Burnley, crews from the fire service, ambulance and police were subjected to yobs attacking them with fireworks and other missiles.
A number of police vehicles were damaged and are now out of action following the incidents which the police have said were 'totally unacceptable'. No-one was injured.
No arrests have been made and inquiries are ongoing to identify those responsible.
M6 closed in both directions after vehicle transporting sheep overturns following crash between Preston and Lancaster
Lytham St Annes care home boss appears in court after death of residents
Flood works outside Penwortham Methodist Church “causing absolute chaos”
The Old Vicarage Care Home: special measures status for Lancashire care home where resident was left lying on floor after falling out of bed
'No-kill' animal shelter forced to explain why they put two healthy dogs to sleep at Blackpool site
“The events of Friday night were totally inexcusable and show an utter lack of respect for emergency service workers who are going above and beyond day in and day out to keep our communities safe.
“Police officers are human beings and many of them live in the communities that they police and protect. They do not come to work to be abused and physically attacked by a small minority of disrespectful people who clearly have no respect for the authorities or indeed the communities that they live in.
“It is only a matter of good fortune that no police officers, paramedics or firefighters were not seriously hurt in last’s nights disgraceful events.
“We will be doing all we can to identify the individuals involved and subject them to the full force of the law.”