Guinea-Bissau says the West African country has arrested two Cape Verdian police officers on suspicion of drug trafficking after the Atlantic Ocean island state demanded clarification on their detention.

Guinea-Bissau Prime Minister Rui Duarte Barros told Parliament on Friday that the two officers were arrested in the capital Bissau on July 12 after their entry without legal status.

On the previous day, Cape Verde's Internal Administration Minister Marisa Morais said the two officers were prevented from leaving after their "routine escort" of a Guinea-Bissau citizen, who had been expelled from the archipelago for drug trafficking.

The minister demanded Bissau explain why they were questioned on Tuesday by Guinea-Bissau's public prosecutor without charges brought against them.

In response, Barros said the Cape Verdian policemen entered Bissau "with fake addresses and false reasons of staying."

"They came to Bissau for holiday without mentioning extradition of a Guinea-Bissau citizen involved in drug trafficking in Cape Verde," the official added.

"The most serious issue is that the two police officers neither informed Guinea-Bissau authorities, nor even reported to the our consulate in Cape Verde, when they were expelling the Guinea- Bissau citizen," Barros said.

The head of the Guinea-Bissau government said the rights of the detainees will be respected, and the duration of their detention will conform to the country's law.

Meanwhile, the Guinea-Bissau League of Human Rights condemned the authorities for detaining the two suspects without presenting them before a judge. It urged the authorities to respect the principle of fairness and the international standards on human rights.

The tension between Cape Verde and Guinea-Bissau is rarely seen as the two Portuguese-speaking countries have maintained a special relationship since decades ago in their struggle for independence.

Guinea-Bissau has been weakened by coups and coup attempts while drug traffickers see their chance to make it a lawless state for cocaine shipped from Latin America to Europe.