ISLAMABAD (AFP) - Pakistan's former military ruler Pervez Musharraf arrived at court on Tuesday for the first time to face charges in a treason case he has denounced as a score-settling exercise by Prime Minister Nawaz Sharif.

The 70-year-old arrived in a heavily protected cavalcade at the National Library in Islamabad where the court has been holding hearings, an AFP photographer said.

No former military leader has appeared in court before and the trial is seen as a test of the supremacy of civilian rule in a country governed for more than half its history by the army after three coups.

Musharraf faces treason charges, which can carry the death penalty, over his suspension of the constitution and imposition of a state of emergency in 2007 while he was president.

He was first ordered before the tribunal on December 24 but had missed repeated hearings since then due to bomb scares and health issues that saw him complain of a heart problem.

Musharraf has challenged the civilian court's right to try a former army chief, saying he is entitled to be dealt with by a military tribunal.

He has accused Prime Minister Sharif, who he ousted in a 1999 coup, of carrying out a "vendetta" and has asked for permission to go abroad for medical treatment, which has been refused.