A DUP member of Northern Ireland's Policing Board has said he is concerned that only a third of PSNI officers are on frontline or community duties.
Jimmy Spratt said officers have told him they have not got enough support when called out to incidents like the one on Friday night in west Belfast.
A hand grenade was thrown at officers called to a robbery in Shaw's Road during the incident.
Dissident republican group Oglaigh na hEireann (ONH) said it was responsible.
"Given the very serious dissident threat, and the very serious indications given by the local commander in relation to Friday night's incident that things will have to be done different today from what they were done on Friday," Mr Spratt said, "I think to me means that there has to be additional officers to actually give back-up, to give cover to police officers who may be tied up for a period of time at serious incidents."
Earlier, Mr Spratt said the fact a hand grenade was used in Friday's attack was very concerning.
"Senior officers are very concerned, they are worried about a shipment (of weapons) having got through, there are serious concerns about that," he said.
"I have been speaking to senior officers and I would be very surprised that there was only one grenade, it is highly likely there are others."