Combat-related deaths in Syria and targeted murders in three other countries have made 2012 one of the deadliest years on record for journalists, according to a US-based group which promotes press freedom.

The Committee to Protect Journalists (CPJ) says, as of mid-December, at least 67 journalists had been killed in direct relation to their work, a more than 40-percent rise from 2011. The group says another 30 deaths are under investigation.