Pervez Musharraf, Pakistan's former military ruler, has been charged with murder of former Prime Minister Benazir Bhutto, who died in a gun and bomb attack in December 2007, court officials say.

The case of Bhutto's murder is one of several that Musharraf is facing since his return from self-imposed exile earlier this year.

"He was charged with murder, criminal conspiracy for murder and facilitation for murder," public prosecutor Chaudhry Azhar said at the anti-terrorism court in Rawalpindi hearing the case on Tuesday.

Musharraf, 69, who attended court proceedings amid high security, denied the charges and the case was adjourned until August 27.

Six other people, including two senior police officers, are also facing charges in the case.

Bringing charges against a former army chief is an unprecedented move in a country ruled for more than half of its history by the military.

The decision by a court in Rawalpindi marks the first time Musharraf, or any former army chief in Pakistan, has been charged with a crime.

Musharraf seized power in a bloodless coup in 1999, and was forced out by a democratically elected government in 2008.

He has been under house arrest at his villa on the edge of the capital Islamabad since April 19, when he returned ahead of a general election to begin campaigning for his All Pakistan Muslim League (APML) party.

Musharraf's legal team dismissed Tuesday's indictment.

"These charges are baseless. We are not afraid of the proceedings. We will follow legal procedures in the court," his lawyer Syeda Afshan Adil said.

Tight security

A large contingent of security forces guarded the area around the court in Rawalpindi, the city where Bhutto was killed while leaving a public rally on December 27, 2007, with roads sealed off for Musharraf's appearance.

"He was brought to the courts under very tight security because of the threats from the Tehreek-e-Taliban Pakistan to his life, and then he was immediately rushed back to his farm house, which has been turned into a sub-jail," reported Al Jazeera's Kamal Hyder in Islamabad.

Other officials linked to the case have also come under threat, with Chaudhry Zulfiqar Ali, the previous special public prosecutor in the case, being shot dead by unidentified gunmen on May 3.

Bhutto, twice elected Prime Minister of Pakistan, was assassinated in a gun and bomb attack after campaigning for elections that were won by her Pakistan People's Party in February 2008.

Musharraf's government blamed the assassination on then Tehreek-e-Taliban Pakistan chief Baitullah Mehsud, who denied any involvement. Mehsud was killed in a US drone attack in 2009.

The new government headed by Nawaz Sharif, whom Musharraf deposed in 1999, has said he should stand trial for treason for subverting the constitution and has appointed a committee to investigate him.

The offence carries the death penalty or life imprisonment.

Musharraf was arrested after returning from exile to stand in the May elections won by Sharif. He was barred from running for parliament because of the legal allegations against him.

He is also wanted over the death of Baloch rebel leader Nawab Akbar Bugti during a military operation in 2006.

Amnesty International has demanded that Pakistan hold Musharraf accountable for all rights violations committed during his rule.