BANGKOK: Internet users have attacked key Thai government websites to protest against plans to introduce a single internet gateway for the country.

More than 100,000 people have signed a petition against the proposal, dubbed the "Great Firewall of Thailand".

It is seen as a way for the ruling military junta to monitor the web and block content.

The websites of the Prime Minister, the Defence Ministry and the Ministry of Information and Communication Technology were brought down late on Wednesday after hackers used social network sites to urge users to go online and continuously click refresh, causing overloads on the sites.

Several other state-owned agencies were also targeted. Most were restored by Thursday.

Internet gateways are the points on a network where a country connects to the worldwide web.

Thailand's internet flowed through a single government-owned gateway until the communications industry was deregulated in 2006, allowing dozens of companies to open their own access points, resulting in dramatically increased internet speeds.

Thailand's average internet speed is 7.5Mbps, which is similar to that in Australia.

However, the junta that seized power in a coup last year had blocked scores of internet sites and increased censorship, despite vowing to expand the country's appeal as a regional internet hub.

Critics say the junta's plans to reduce internet access to a single gateway controlled by state-owned CAT Telecom will curb freedoms and risks destroying the country's IT industry.

As criticism grew after details of the plan were inadvertently made public last week, Deputy Prime Minister Prajin Juntong told reporters no "firm decisions have been made" on the proposal.