From secularists to religious conservatives, there is one thing nearly all Pakistanis seem to agree on -- the U.S.-led war in Iraq is unjust and must be opposed.

Yet Pakistan's traditional political parties and the pro-military government have remained largely silent on the war, allowing a resurgent coalition of Islamic hard-liners to fill the void, turning anger over the conflict into their rallying cry against the West.

The coalition, called the Muthida Majlis-e-Amal, or MMA, has organized massive anti-war demonstrations in the country's four main cities, drawing well over 100,000 people into the streets each time. Some 40,000 people took part in a fifth protest in the southwestern town of Quetta on Wednesday.

"The so-called mainstream parties have abstained from the whole issue of Iraq because they have not wanted to antagonize Washington," said Afrasiab Khattak, the Peshawar-based head of the Human Rights Commission of Pakistan. "So there is a vacuum which is being filled by the MMA. They have an open field."

The religious coalition sprang to prominence last year during nationwide elections amid deep anger over U.S. bombing in neighboring Afghanistan and disgust at President Pervez Musharraf's decision to abandon the Taliban regime and support Washington.

The coalition came in third nationwide, by far its best-ever showing, and won power outright in the ultraconservative North West Frontier Province, of which Peshawar is the capital.

"They got a big advantage from opposing the war in Afghanistan and they are getting even more support now from illiterate people who are angry about Iraq," said Bashir Ahmed Bilour, the president of the Awami National Party, the secular party that lost power to the MMA in the province. "They will get more and more aggressive."

The national government has toed a careful line on Iraq, calling for peace but also criticizing Iraqi President Saddam Hussein for failing to disarm. The official ambivalence has been met with anger by many in this deeply religious country who have demanded an outright condemnation of Washington.

The religious coalition has vowed to institute Islamic law, or Shariah, in the North West Frontier, and is planning to unveil a package of Islamic bills to the provincial legislature later this month.

Hardline leaders haven't said whether they plan to institute punishments like public stonings or cutting off thieves' hands, but liberals worry the Iraq war will only embolden them.

"The Shariah package is arriving at a time when opinions are very strongly against the West and everything the West stands for," said Khattak. "Definitely, the MMA is using the climate to push their own agenda. People are more likely to buy their stance because the anger over Iraq has closed minds to rational arguments."

For their part, MMA leaders say they are only speaking their conscience, and giving voice to what the vast majority of Pakistan's 140 million people believe.

"The MMA represents the people and their sentiments, while the government is weak," leading MMA official Qazi Hussain Ahmed told The Associated Press after a recent conference in Peshawar on the impact of the Iraq war on the Muslim world. "Naturally, our position on Iraq has already increased our popularity."