TAIPEI (AFP) - Taiwanese authorities on Sunday strengthened barriers around the presidential office after a truck was rammed into the tightly guarded premises in an attempted suicide attack.

More military police with automatic rifles were deployed and a line of huge granite blocks was lifted into place to reinforce existing barriers outside the building, televised images showed.

The incident, described by police as an attempted suicide attack, was the worst of its type on the building. It happened around 5am on Saturday when Chang Teh-cheng drove a 35-tonne truck through several sets of barricades, police said.

At high speed, the vehicle ascended a set of steps before being stopped by a bullet-proof screen and becoming stuck in the gate leading to the office's main building, they said.

Chang, 41, was severely injured and taken to hospital. No one else was hurt but the attack prompted an investigation and an immediate tightening of security.

Local media speculated that damage and casualties could have been serious had Chang been driving an oil tanker.

President Ma Ying-jeou was away on a state visit to Sao Tome and Principe in Africa. He has been notified of the incident, his spokeswoman said.

An initial police investigation ruled out political motives. Chang had been given a 40-day jail term in 2011 for fighting with a relative from his second marriage which ended in divorce.

"He was not happy with the court ruling," a police officer told reporters, adding that computer data seized by police showed that Chang had planned the attack for a year.

The police found a clue to his plan when he posted a car accident report also involving a truck on his Facebook page in March.

He wrote: "Perhaps I would give a show too and the name would be called "Chueh Ming Chung Chieh Chan" - the Chinese-language title of the American horror film Final Destination 5.