QUETTA, Pakistan: Hateful graffiti messages against Shiite Muslims are scrawled along main roads. The striped flags of a banned militant faction accused of hundreds of murders flutter from homes.

These are the outskirts of Quetta in Pakistan, from where Shiite leaders say Sunni extremists towed a giant bomb by tractor to kill 90 Shiite Hazaras on February 16, after dispatching suicide bombers to kill 92 others at a snooker hall a month earlier.

Lashkar-e-Jhangvi, a militant group officially banned by the government in 2002, claimed responsibility for both attacks. Local Shiites say they know who the organisers are, and where they live, and yet the authorities do nothing.

An AFP reporter saw no sign of police or paramilitary in Akhtarabad, the run-down neighbourhood from where Shiites claim the bombers drove the giant bomb.

Nor was there a security presence in Killi Kambrani and Killi Badeni, dens of suspected kidnappers and criminals, covered in slogans for jihad and Ahle Sunnat Wal Jamaat (ASWJ), described as the "political wing" of LeJ.

Bombers determined to exterminate Shiites have slaughtered more than 250 Pakistanis since January 10 and questions are being asked about possible political and military collusion.

Pakistan has an abysmal track record of convicting extremists, and there is growing alarm about perceived apathy towards attacks on Shiites, which are similar to those that fuelled civil war in Iraq.

"Akhtarabad is their hub and main hideout. Everybody knows they come from there to attack Hazaras but nothing has been done," said Shiite community leader Syed Mussarrat Hussein in Quetta, the capital of the troubled southwestern province of Baluchistan.

Daud Agha, local president of the Shia Conference, said tip-offs about impending attacks are ignored and the ASWJ tolerated.

Amnesty International has said the failure of the authorities to bring those responsible for sectarian violence to justice "sends the signal that they can continue to commit these outrageous abuses with impunity".

So how and why does LeJ operate with such apparent freedom? There are many theories.

The worst violence is concentrated in Baluchistan, fuelling accusations that the military turns a blind eye or even encourages LeJ operatives, to distract attention from a six-year separatist insurgency.

"LeJ got stronger in Baluchistan after the start of the Baluch insurgency," says Anwar Sajidi, a Baluch rights activist and chief editor of Quetta-based newspaper Intikhab.

"The government is supporting LeJ as a counter-insurgency strategy to show the world that sectarian violence is also on the rise and the Baluch separatist movement is not the only reason for killings."

LeJ, which is linked to Al-Qaeda, was created in the 1990s out of the same pool of fighters trained and nurtured by Pakistan, Saudi Arabia and the United States in the 1980s war against the Soviets in Afghanistan.

Last month the chief military spokesman categorically denied the armed forces were in contact with militants, including the LeJ.

But despite Pakistan joining the US-led "war on terror" after the 9/11 attacks, the armed forces continue to be dogged by allegations of playing a double game.

LeJ founder and ASWJ vice president Malik Ishaq has been accused in more than 40 murder cases but was free until being taken into custody on February 23 for posing a risk to law and order.

Others say LeJ is protected because of the electoral support it can harness in southern districts of central Punjab province, a key battleground in upcoming national elections where the Pakistan Muslim League-N is in power.

"This politics of expediency may win the party a few more seats in the upcoming elections, but the move would provide further space to religious extremism already on the rise," author Zahid Hussain wrote in Dawn newspaper.

There is little to distinguish the ASWJ from LeJ in public.

"Lashkar-e-Jhangvi was created in reaction to injustices by the government," says Ramzan Mengal, the Baluchistan president of the ASWJ.

"We can ask the LeJ men to negotiate with the government but the authorities will have to stop being influenced by Shias."

A senior police official in Quetta told AFP his force was too weak to act, because the LeJ and ASWJ had too much financial and logistical support.

Until the government develops a "multi-pronged" strategy to shut down their support networks, he warned, Shiites will continue to be slaughtered.

Many people in Baluchistan say there is an international element to the violence, believing that Sunni Saudi Arabia and Shiite Iran are fighting a proxy war on Pakistani soil.

Religious schools that have educated millions of Pakistanis in a hardline Sunni interpretation of Islam are also partly to blame.

"There are hundreds of seminaries in the country who produce thousands of extremists every year," the Quetta police official said.