MOSCOW (AP) _ An earthquake struck the Soviet Central Asian republic of Tadzhikistan, leveling a hospital, factories and office buildings and causing ''loss of life,'' the official news Soviet news media reported today.

They did not say how many people were killed or injured or give an assessment of the damage. But the report of deaths indicated that the casualty toll from the Sunday quake may be heavy.

''The earthquake resulted in the destruction of production and office buildings, housing and socio-cultural and welfare facilities in Kairakum and in Khodzhent district,'' the Tass news agency said. ''There is loss of life and there are injured. The necessary aid is being given to the quake victims and emergency rescue operations are being conducted.''

The government newspaper Izvestia said ''people suffered'' but gave no details of casualties. It said that a hospital in Gafurov collapsed but that the patients already had been evacuated.

Carpet and silk manufacturing works in Leninabad also were damaged, the newspaper said.

The epicenter of the quake, and the most heavily damaged area, was reported to be 145 miles northeast of the Tadzhik capital of Dushanbe, around the village of Kairakum.

In Golden, Colo., Wallace Jacobs of the U.S. Geological Survey's National Earthquake Information Center said the quake registered 5.8 on the open-ended Richter scale, signifying ground motion strong enough to cause considerable damage. Sweden's Uppsala Seismological Institute measured it at 6.2.

Tass said the earthquake measured 8 points on the Soviet 12-point scale at its epicenter, between 3 and 4 points in Dushanbe and nearly 5 points in the Uzbek capital of Tashkent.

An 8-point quake on the Soviet scale is enough to cause severe damage and heavy loss of life. The worst quake in Soviet history measured 9 and leveled the city of Ashkabad in October 1948.

Tass said that around Kairakum, ''adobe houses were destroyed in villages and a landslide swept away an asphalt-surfaced road.''

Tass said the quake struck at 7 p.m. Moscow time (noon EDT). This is 10 p.m. in Central Asia, a time when many villagers would be home and possibly sleeping.

It was not clear why there was a 17-hour delay in reporting the quake in Moscow, but one possible explanation was that communications and power lines had been destroyed.