A court in the Pakistani city of Lahore has upheld a judgement which gives two men the death penalty for their involvement in the killing of more than 20 minority Shia Muslims.

The men, who are Sunni Muslims, opened fire at a Shia religious ceremony two years ago.

Sectarian violence in the county's largest province, Punjab, has claimed more than 900 lives over the past decade.

The two-member bench of the Lahore High Court upheld an earlier judgement by an anti-terrorism court which sentenced the two men, Muhammad Aziz and Haroon Rasheed, to death.

Another four men who were also involved in the attack but escaped, were declared legal offenders by the court in their absence.

However, police say one of the four has recently been arrested and will now face a separate trial.

Attack

The case dates back to two years ago, when the men carried guns into the Mominpura cemetery in Lahore, where a Shia religious ceremony was taking place.

They opened fire, killing 22 people, and wounding nearly 50.

The attackers were later identified as Sunni Muslims, although it remains unclear whether they were members of a larger organised group or acting alone.

A hardline Sunni organisation, Sipah-e-Sahaba Pakistan, which is frequently blamed for attacks on Shias, denied any involvement in the killings.

Last October, the then Chief Minister of Punjab, Shahbaz Sharif caused controversy by suggesting the attackers may have been trained in a Taleban camp in Afghanistan.

But the order passed by the Lahore High Court does not mention any possible Afghan connection.