The embassy was bombed amid anger over cartoons of the Prophet Mohammed published in a Danish newspaper [EPA]

A Pakistani court has acquitted three men accused of involvement in a deadly suicide car bomb attack near the Danish embassy in Islamabad in 2008.

The court acquitted the men on the basis of "insufficient" evidence.  Prosecutors have said they will appeal against the verdict.

Mohammad Tayyab, a senior prosecuter, said 32 witnesses had been called, two of them testifying that they saw suspects Qari Ilyas and Shamsul Haq signalling the suicide attacker towards the target as they sat in a car.

"But still the judge found insufficient evidence," said Tayyab.

Six people were killed in the attack, including a Dane, and about 27 wounded when a car bomb exploded outside the embassy in June 2008.

The bombing came amid anger in the Muslim world over cartoons of the Prophet Mohammed first printed in Danish newspapers in 2005.

The explosion damaged the mission and the residences of the Indian and Dutch ambassadors, and almost destroyed a nearby UN agency.

'Strong case'

Tayyab said that the suspects were arrested a few months after the attack in a separate case, and during questioning they admitted their role in the bombing.

"The court had objected that during the identification parade of the accused men, required procedure was not followed, which is just a technicality," said Tayyab.

"We believe our case is very strong and the high court will analyse our evidence again and decide the case in our favour." 

Al-Qaeda claimed responsibility for the attack in a video, saying one of the bombers had come from Saudi Arabia.

Suspects in high-profile cases are frequently acquitted by Pakistani courts for lack of evidence or on other grounds.

Critics blame this on law enforcement agencies' inefficiency and outdated investigative methods.

In May, a Pakistani court freed four men put on trial over the 2008 bombing of the five-star Marriott hotel in Islamabad that killed at least 60 people, saying the prosecution had failed to prove its case.