YANGON, MYANMAR - The military junta forged ahead Saturday with a constitutional referendum intended to cement its power after a campaign of arm-twisting and intimidation, even as it continued to restrict foreign aid shipments to survivors of last week's devastating cyclone.

The junta is refusing to grant entry to aid workers who relief officials say are crucial to preventing further deaths from disease among an estimated 1.5 million victims.

By Saturday, the military had not released two U.N. World Food Program shipments that arrived Friday, according to a spokesman for the program. Several aid flights have landed in Yangon or are en route, the spokesman said, and supplies from other countries were also on the way.

But the aid amounted to about one-tenth of what is needed, said Paul Risley, a spokesman for the World Food Program.

The focus for the military junta was on the referendum for a constitution that is designed to legitimize and perpetuate military rule. Residents said the vote followed a campaign of coercion mixed with propaganda. The military appeared to be diverting some resources from cyclone victims to the referendum.

There were a number of reports of "pre-balloting," in which employees of enterprises or government offices were required to vote ahead of time under the eye of their supervisors.

The referendum is intended to lead to a multiparty election and a nominally civilian government. But it allots 25 percent of parliamentary seats to the military, gives the military control of key ministries and allows the military to seize control in a time of emergency.

Meanwhile, in the aftermath of the recent cyclone, small groups of residents in the main city, Yangon, banded together to distribute aid, but one said the authorities were sometimes confiscating supplies.

While major shipments of supplies remained blocked, the local staffs of international agencies struggled to coordinate their work and to distribute the limited emergency stocks available in the country. State television showed military officers handing out supplies, to the applause of bystanders. It also broadcast a video of two women singing a pop song whose lyrics translated as: "Let's go to cast a vote. With sincere thoughts for happy days. Let's go to cast a vote."

The government newspaper, The New Light of Myanmar, devoted much of its front page to photographs of military leaders distributing aid and comforting survivors, under the headline, "Lt. Gen. Myint Swe provides food, medicines to storm-hit regions." But above the pictures was a reminder: "To approve the state Constitution is a national duty of the entire people today. Let us all cast 'Yes' vote in the national interest."