"At moment Colombo has been given more policemen than other areas.
But that is not enough, Inspector General Victor Perera told journalists.
"They are over worked. Then their effectiveness is reduced.
He said recruitment and training takes times as a policeman is expected to join a long term national service spanning four decades.
"When new trained recruits come we put most of them to work in Colombo after allocating them for other essential services," Perera said.
"But I am still not satisfied. To fill this gap we expect support from the public.
We can never solve this problem with policemen alone."
He said security in Colombo has been beefed up following a string of recent bomb attacks.
Police had imported explosive detectors at the cost of 3.
6 million rupees each (thirty three thousand US dollars) and they are being deployed at check points and busy public areas.
Perera said the police was also looking at installing close circuit television systems at key poin