Three Vietnamese bloggers were convicted of charges over articles critical to the government, the latest heavy handed swipe at online free speech in the communist state.

Nguyen Van Hai and two fellow bloggers were found guilty by a Vietnamese court after a one-day trial, AP reported. Mr. Nguyen Ban Hai was sentenced to 12 years in prison while Phan Thanh Hai was given a four-year sentence. Ta Phong Tan, whose mother set herself on fire in protest over the charges, was sentenced to 10 years. The bloggers wrote about political, economic and social issues in Vietnam as members of the “Free Journalist Club”.

A growing number of Vietnam’s population is using the internet, striking a cord with the government in what it sees as a highway for information that could “disrupt the state’s public security” amid an economic slowdown and ballooning debt.

A Western diplomat claimed that the crackdown is “designed to create a chilling effect”. The US embassy, in a statement, said that it was “deeply concerned” and urged the Vietnamese government to free the bloggers. The government refused to comment. Early last month, Vietnam blocked blogs which published posts ‘critical’ to the Communist government.