Katangan rebels are now consolidating their hold on Zaire's southern Shaba Province, setting up a civil administration, trying to maintain social services, and brining in new supplies, intelligence sources here say.

These sources claim the Katangan entrenchment is in preparation for an attack on Kolwezi, Zaire's valuable mining center. If government forces make a stand at Kolwezi it would be the first significant fighting in the month-old rebellion. Until now Ziarian troops have put up little resistance.

Since the fall more than a week ago of Mutshatsha, the last town before Kolwezi, there has been a lull in military activity in Shaba. But the pause does not reflect a military slowdown, the sources claim.

Perhaps the most significant sign of the rebels' highly organized strategy is the reopening of the railway link between Mutshatsha and Dilolo, a Zaire town on the Angolan border, Dilolo is believed to be the new headquarters of Katangan forces, the former policemen in Shaba (formerly called Katanga) who beked the secessionist movement of Moise Tshombe in the southeast region after the Belgian Congo gained independance in 1960.

The railroad could speed up the resupplying of material and reinforcements from bases in Angola. It could also provide a covered means of bringing in heavier equipment.

It appears that the Katangans are attempting to maintain normalcy in the third of Shaba Province that they have taken since March 8. The few Europeans in the area have communicated via radio links that there has been little change in services since the rebels came in.

A railway employee in Mutshatsha, who witnessed the takeover, said the rebels allowed him to leave when he explained that he was not a member of the local Lunda tribe, of which the Katangan are members.

He walked to the next railroad junction and was the first to verify reports that the town had been captured. He reported a "peaceful" takeover.

Meanwhile, the tension here in the capital, some 1,500 miles away, has mounted noticeably since Sunday when attendance at government-sponsored rally designed to show support for the troubled administration of President Mobutu Sese Secko fell far short of expectations.

Over the past three days the local media has increased its denunciation of the foreign press for "distorted" reporting that exaggerated the military situation and played into the hands of the attackers. On Monday, the government ordered Associated Press correspondent Michael Goldsmith to leave the country.

Another Western reporter, Peter Seidlitz of (West) Germany's Sueddeutsche Zeitung, was told to go after only two days in Zaire. Seidlitz had not yet file a story. Security police, however, questioned him about an Angolian visa in his passport, which he used over 18 months ago.

A French television crew had its film of Kinshasa's main boulevard confiscated yesterday. A CBS-TV crew was threatened with jail today while filming Kinshasa's suburbs. After interrogation they were released buttheir film was confiscated.

A local journalist, Bedouin Kayembe, who reports for United Press International and Associated Press, was arrested Monday. Security police have refused to disclose the charges.

The local press has all but ignored the growing military threat in the south. The only way residents here know there is continuing trouble is through foreign papers and radio broadcasts and by interference from the government's criticism of foreign reporting. This lack of news has led to a flood of rumors.

Among the foreign community, there ismuch speculation now on "when" rather than "whether" the government will change.

As a Equopean businessman who has been in Zaire for more than 20 years said yesterday: "When it started I thought (mobutu) had held such a tight rein on this country for so long that he could withstand this attack. Now I have serious doubts. It's all building up against him, and not only in Shaba. I feel it among my African employees and associates."