COLOMBO (AFP) - International rights groups on Thursday condemned moves by Sri Lanka's government to introduce a code of ethics for journalists, saying it would further undermine press freedom.

Local journalists have already criticised the planned media code, which is set to be adopted shortly by lawmakers, as being too sweeping and now international advocacy groups have added their voice to the criticism.

"Sri Lankan journalists are already under enormous pressure not to be critical of the government, and the vagueness of this code will likely lead to greater self-censorship to avoid government retaliation," said Brad Adams, the Asia director of Human Rights Watch.

The New York-based Committee to Protect Journalists also criticised President Mahinda Rajapaske's government for focusing on such a code at a time when it is preparing to host a Commonwealth summit in November.

"Mahinda Rajapakse's regime should stop expending energy on imposing a code that would further suppress the country's already dwindling free press," said the CPJ's Asia programme coordinator Bob Dietz.

The new code drawn up by the information ministry seeks to prohibit "material against the integrity of the Executive, Judiciary and Legislature".

It also warns against the publication of content that "offends against expectations of the public, morality of the country or tend to lower the standards of public taste and morality".

Information Minister Keheliya Rambukwella said that the new code would not be legally enforceable but instead "would only be a memorandum of understanding".

Sri Lanka was ranked 162 out of 179 countries in a recent press freedom index compiled by the Paris-based Reporters without Borders and media rights groups say journalists have been forced to self-censor their work due to fear of attacks.

At least 26 journalists have already fled Sri Lanka in the past five years to escape threats, intimidation, violence, and imprisonment, according to CPJ.

At least five journalists have been killed in the same period.