BAGHDAD, 20 August 2005 — Negotiators sought yesterday to reach agreement on the draft of Iraq’s new constitution by next week’s deadline, as Sunni Arabs and followers of a radical Shiite cleric joined forces to mount protests against the charter’s proposed federal structure.

With Sunni Arab negotiators still holding out against federalism and some other Shiite and Kurdish proposals, pressure of a different kind was mounting on Sunnis who support the constitutional process.

Unidentified gunmen yesterday kidnapped three members of the largest Sunni Muslim grouping, the Iraqi Islamic Party, and later executed them.

The masked gunmen blocked a major road in front of Dhi Al-Nourein Mosque, then brought the three out of cars. They forced them to stand against a wall, sprayed them with automatic fire and fled.

The party has been urging Sunni Muslims in recent weeks to register to vote in an October referendum on the new constitution. Many Sunni Muslims boycotted the Jan. 30 elections following threats by insurgents and calls by clerics not to do so.

And in the tense city of Ramadi, masked gunmen burst into the Sunni grand mosque as religious, political, and tribal leaders met to discuss possible Sunni participation in the constitutional process.

The gunmen asked participants to end their meeting and then opened fire on them, said Omar Seri, secretary of the governor of Anbar province. Three members of the Sunni Association of Muslim Scholars and a bodyguard were injured, Seri said.

More than 1,000 people yesterday rallied in Baqouba, northeast of Baghdad, to protest the proposed constitution. The demonstrators chanted slogans against the proposed division of Iraq and called for a centralized form of government.

In Baghdad, anti-federal protests were held in several districts. In mostly Shiite Sadr City, about 1,000 people demonstrated waving Iraqi and Shiite flags and chanting “No to separation, yes to unity.”

“We reject federalism under occupation. Federalism does not represent our people’s aspirations,” said Abdelzahra Al-Sueidi, an aide to radical cleric Shiite Muqtada Al-Sadr. In Kazimiyah — another Shiite bastion — hundreds of Al-Sadr supporters turned out at a protest, flying national flags and holding up banners reading “We want a united and stable Iraq.”

“After all, we are one united people whether we are Sunnis or Shiites, Kurds or Arabs,” Hazim Al-A’araji, another Al-Sadr aide, told the congregation in a Kazimiyah Mosque during Friday prayers. The biggest Shiite political party — the Supreme Council for the Islamic Revolution in Iraq — supports creation of a federal region in the Shiite-dominated areas of central and southern Iraq, including major oil fields.