Vietnam jailed 13 pro-democracy activists convicted of plotting to overthrow the communist regime, the latest crackdown on dissent in the authoritarian state.

A Vietnamese court found the accused – including Catholics, bloggers and students – guilty of subversion and sentenced them to jail terms ranging from three to thirteen years on Wednesday.

Three defendants had been sentenced to thirteen years while the others received terms of three to eight years. Another defendant was given a three-year suspended sentence which equates to house arrest in Vietnam, defense lawyer Ha Huy Son told AFP.

The activists were arrested in 2011 on accusations of involvement with a banned pro-democracy group run out of California, the New York Times says.

The crackdown drew criticism from the US which describes it as a “disturbing human rights trend in Vietnam.”

The US Embassy in Hanoi said in a statement that it was “deeply troubled” by the convictions.

Rights groups say dozens of peaceful political activists had been jailed since the Communist regime began a crackdown on freedom of expression in 2009.

“The conviction of more peaceful activists is another example of a government that is increasingly afraid of the opinions of its own people,” says Brad Adams, Asia director at New York-based Human Rights Watch.

On Tuesday, a schoolgirl was suspended for posting on Facebook a parody of a famous speech by revered leader Ho Chi Minh amid the strictly regulated media.