In Standard English (StdE), youth as a countable noun — that is, singular a youth or plural some youths — refers disapprovingly to young males, usually teenagers, engaged in antisocial or criminal behaviour. It is therefore often found in collocations such as a gang of youths. (This is different from the collective-noun sense of the word, e.g. the youth of Singapore, meaning ‘young people in Singapore taken considered as a group’.)
In Singapore English (SgE), however, youth as a countable noun refers to nothing more than ‘young people’, both female and male. As the extracts above show (Straits Times, both 11 January 2010), the word has no negative connotations: in fact the photographs show young people, female as well as male, doing good deeds.
A linguistic purist might put the SgE usage down to sheer ignorance, but a descriptive linguist would probably argue that it is simply a feature of SgE which sets it apart from other varieties.