Troops firing tear-gas grenades stormed the Vatican's Embassy (Apostolic Nunciature) tonight and overpowered gunmen in a bid to release four nuns and an embassy employe being held hostage, the official Cuban news agency said.

One of the hostages was killed in the firefight, the agency said.

In a four-paragraph dispatch, the Prensa Latina news agency said armed "antisocial delinquents" seized the Vatican's mission and took five hostages. Although it gave no reason for the seizure, it was believed they were seeking political asylum.

Agents from the Ministry of Interior, under fire from the gunmen, charged into the mission and rescued the four nuns, the dispatch said. The office employe, a Cuban citizen, was killed but the dispatch did not explain how.

Several intruders resisted arrest as they staggered, half-blinded and retching, out of the gas-filled building. At least one was wounded in a struggle with the security forces and was taken away bleeding and unconscious.

Interior Minister Ramiro Valdes, clad in his military uniform, personally directed a five-hour police operation after the group climbed into the Apostolic Nunciature firing four or five shots into the air.

Police patroled the area during the operation, preventing foreign reporters and the public from entering the street where the mission is located, in Havana's residential Miramar district.

The dispatch, the last report of the night released by the news agency, did not say how many people were involved in seizing the mission but said all of them were captured. It was believed that at least 14 gunmen entered the mission.

It stated "under no concept nor circumstance" will Cuba allow anyone to leave the country after a violent act, such as an embassy seizure.

But it briefly recalled the takeover last spring of the Peruvian and Venezuelan embassies by thousands of Cubans who later were allowed to travel to the United States.

Last April, more than 10,000 Cubans crowded into the grounds of the Peruvian Embassy in Havana seeking asylum. This led to a sealift of more than 120,000 refugees to Florida.

Hundreds of thousands who applied to leave are now stranded in Cuba because President Fidel Castro's government ended the sealift in September. Many of them are reported to have lost their jobs for seeking to go to the United States.

Two weeks ago, nine people sought asylum in the Jamaican Embassy in two separate attempts. They were persuaded to leave because Jamaica has no asylum treaty with Cuba. They were detained by police.