PRAGUE, Czechoslovakia (AP) _ Seven Cubans, including five opposition activists, have sought refuge in Czechoslovakia's Havana Embassy, the state CTK news agency reported today.

CTK's French-language service said the activists entered the embassy to demand Czech guarantees that they could leave Cuba for a planned weeklong visit to Czechoslovakia beginning July 15.

The visit was to be part of a tour of Europe and the United States ''aimed at spreading the aims and programs of the Cuban opposition movement,'' CTK said. It did not elaborate.

Zdenek Smrkovsky, a foreign ministry official in Prague, said the five men walked inside the embassy through the main door on Monday without incident. He said as far as he knew, there were no other cases of people seeking refuge in any other embassies in Havana.

He said the men ''did not seek political asylum.''

Two more Cubans, who claimed to be students, climbed over the embassy's fence later and did ask for political asylum, CTK said. Cuban police then cordoned off the street leading to the mission, the news agency said.

It identified the two as Igor Campana and Alejandro R. Lugo.

Yugoslavia's Tanjug news agency quoted an unidentified spokesperson at the Cuban Foreign Ministry as saying the five opposition leaders ''must leave the embassy or stay there as long as the diplomatic mission would have them.'' He was quoted before the last two people entered the embassy.

The activists belong to the Cuban Human Rights Committee, the Cuban Christian Democratic Movement and other opposition groups, CTK said.

Cuba and Czechoslovakia were close allies before last winter's democratic revolution swept Czechoslovakia's Communist regime from power.