Russian television showed footage of up to 100 students in the embassy, who said they would continue their protest until all debts owed to them were paid.

They said the 200-odd Guinea Bissau students in Russia had not received their $60-a-month stipends for a year.

Diplomat Rogerio Herbert said the students' demands had been passed on.

The Soviet authorities invited large numbers of Third World students to study free in the USSR, as a means of winning influence abroad.

Numbers have declined, but many overseas students still come to Russia to study. However, some complain of severe financial problems.

Police not involved

Moscow police received reports at 1230 local time (0930 GMT) that a group of young people forced their way into the ambassador's apartment, which also serves as an embassy.

Embassy staff refused offers of help from the police, Russian media reported.

It was not clear what the hostage-takers intended to do if their demands were not met, although some reports said they were on hunger-strike.

"The ambassador is our hostage, he isn't going anywhere. We will shut all the doors and the diplomatic service will not work until we recover our debt," a student named as Silvio Bravo told the TV.

Guinea Bissau is one of the poorest countries in the world, although the former Portuguese colony was once a model for economic development in Africa.