BANJUL, March 28 (Reuters) - Gambian police sealed off the offices of the tiny West African country's Independent newspaper and arrested its entire staff on Tuesday, a day after the paper printed two articles critical of President Yahya Jammeh.

Most employees were released after questioning but Managing Director Madi Ceesay -- who is also president of the Gambia Press Union -- and Editor Musa Saidy Khan remained in detention on Tuesday afternoon, members of the newspaper's staff said.

The arrests were a further sign of tension in the poor former British colony less than a week after the government said it had foiled a coup plot and launched a crackdown in which 28 people, including 15 army officers, have been arrested.

No official reason was given for the action against the bi-weekly newspaper, but staff said they suspected it was linked to articles critical of Jammeh.

Monday's edition carried an article debating whether Jammeh was himself richer than the state of Gambia, as asserted by opposition politician Halifa Sallah at a rally over the weekend.

Newly-appointed Ceesay wrote in another article that Gambians were poorer than before Jammeh came to power in a bloodless coup 12 years ago.

Jammeh's government said last week it had foiled a coup plot, and a group of senior military officials appeared on state television on Monday confessing to being part of the plot.

One read out a statement he said would have been broadcast following the coup, complaining of economic and social degradation and rising living costs since Jammeh took power.

With around 1.5 million people, Gambia is a narrow sliver extending along the Gambia river, sandwiched between north and south halves of Senegal, and depends on peanut farming, fishing and tourism for its livelihood.

Since last week the government has named new intelligence and defence chiefs in an apparent purge of top security posts.

Opponents accuse Jammeh of a range of human rights abuses as well as rigging previous elections.

He opened his campaign for the 2001 presidential vote by saying he had already won and threatening to shoot anyone who disrupted polling, and is expected to seek a third elected term in elections due in October 2006.