KUALA LUMPUR (AFP) - Malaysian courts on Friday charged three men and a woman from the Muslim-majority country over promoting terrorism in strife-torn Syria.

The four were among 11 Malaysians arrested since late last month in an operation to crack down on Islamic terror suspects, who using claims of humanitarian work as cover.

Two others of those arrested remain under investigation, while five will be released, according to police.

A prosecutor said the three men and a woman, all in their 20s, were charged in separate courts across the country with "promoting or supporting jihad (holy war) to go to Syria".

He declined to be named because he is not allowed to make official statements.

"It's a Malaysian-based group that is linked with international terrorist groups," he said, declining to give further details.

If found guilty, the accused face up to 30 years in prison, he added.

Malaysia practises moderate Islam, but concern has risen in the multi-faith Southeast Asian nation over perceived Islamisation.

Malaysia has also been home to several suspected key figures in militant Islamic groups.

Police have said they are probing terrorism as one possible reason for the March 8 disappearance of flight MH370, but the recent arrests are not related to this.

The Malaysia Airlines plane is believed to have crashed into the southern Indian Ocean with 239 people aboard, but no sign of wreckage has yet been found.