Hundreds of Singaporeans hold a candlelight vigil to protest the looming execution of two Malaysians convicted of drug offences, as the United Nations urges the city-state to spare them. Nagaenthran K. Dharmalingam, a mentally disabled man arrested in 2009 for heroin-trafficking, is to be hanged on Wednesday despite an international outcry. Another Malaysian, Datchinamurthy Kataiah, is scheduled to be executed two days later, according to campaigners. More than 400 Singaporeans gathered late Monday at "Speakers' Corner" in a downtown park, the only place in the tightly controlled city-state where protests are allowed without prior police approval.  IMAGES AND SOUNDBITES