President Mohammed Zia ul-Haq, Pakistan's Army chief of staff and chief martial law administrator, today "postponed indefinitely" long-promised elections scheduled for next month.

He also disbanded all political parties and prohibited civilian political activities.

Tightening its martial law control over the country, Pakistan's Army also closed newspapers "which have been poisoning the minds of the people" and imposed strict censorship on the Pakistani press.

Zia said in a nationwide radio and television address that he acted because many politicians "preferred party interests to national interests."

He made his move after some of the best-known political parties refused to take part in the Nov. 17, election because of new registration requirements.

Zia's action also apparently came in response to a surprising show of strength in elections for nonpartisan local bodies by members of the Pakistan People's Party of former prime minister Zulfiqar Ali Bhutto, who was executed by the Zia government in March after being found guilty of murder and conspiracy charges.

Zia's actions tonight further increased the political volatility in an area of the world that has become increasingly unstable because of crises in the horn of Africa, Iran, Afghanistan and India.

Zia, however, insisted that his martial law goverment is as committed now to returning Pakistan to democratic civillian control as it was in July 1977, when it ousted Bhutto in the midst of widespread civil unrest against his government and an insurgency in the province of Baluchistan.

"My faith in democracy remains unimpaired and the armed forces even now do not want to remain in power," he said.

"It is their desire even now that elected officials should run the affairs of the country. But no responsible person can allow, as was done in the past, the destruction of democracy in the name of democracy and chaos, and terrorism in the name of politics."

He said steps will be taken "at the appropriate time" to restore the democratic process. But, he added, that will take "some time."

Zia has consistently stated that he expected "positive results" from an election to ensure that Pakistan remains an Islamic state with a stable government.

"The main need of this country," he said tonight, "is an Islamic, democratic and stable government for which elections for the sake of elections have no meaning."

While postponement of the election was expected here, the new widespread powers given the martial law authorities -- especially the press censorship -- surprised many observers.

Since political parties and political activities are illegal, a government spokesman said, any reporting of political comment in newspapers and magazines is banned. The censorship order also bars publication of anything that "is prejudicial to Islamic ideology or the sovereignty, integrity and security of Pakistan."

While the censorship order applies only to Pakistani papers, the government spokesman said foreign correspondents are expected not to file stories that would violate it. But the spokesman said outgoing dispatches will not be censored.

Violators can be punished by to 10 years of "rigorous imprisonment," fines and up to 25 lashes. Zia also strengthened the powers of the martial law court by banning challenges in civil courts to their rulings. This, he said, would ensure that no one found guilty would "escape the stringent and prompt punishment of martial law."

Since there have been reports that civil police officers have taken bribes to keep cases from the martial law courts, Zia said that only high martial law authorities not will be allowed to decide where a case should be heard.

On the economic front, Zia promised to continue a policy of a mixed economy, with the government running only certain key industries. He suggested that his government may begin denationalizing some industries.

He moved to end labor unrest by banning union strikes and management lockouts and said that in the face of rampaging inflation he will establish local "cells" to monitor the prices of essential goods.

Zia also pledged to move ahead faster in the process of making Pakistan an Islamic state.