Authorities in Malawi have arrested at least two opposition party leaders and two former security officials on charges they were plotting to overthrow the government.

Government officials Tuesday confirmed the arrests of the United Democratic Front's secretary-general, Kennedy Mwakwangwala, and executive member John Chikakwiya. Others arrested included former army commander Joseph Chimbayo and former police chief Joseph Aironi.

All those arrested served under the administration of former President Bakili Muluzi from 1994 to 2004.

The UDF has endorsed Muluzi to run next year for president against the country's current leader, Bingu wa Mutharika.

The UDF and a fellow opposition party, Malawi Congress, boycotted the country's opening parliamentary session last month. The parties were protesting attempts by Mr. Mutharika's Democratic Progressive Party to persuade opponents to switch party affiliation.

The opposition parties say they want the speaker of parliament to remove the DPP members under a constitutional provision that prevents floor-crossing. If successful, they would have enough votes to support a no-confidence vote against President Mutharika.

Mr. Mutharika says the opposition wants to remove his members of parliament in order to impeach him.

He was elected in 2004 as a UDF candidate, but broke away shortly thereafter to form his own political party. He did so after accusing his political associates of blocking his anti-corruption effort.

Some information for this report was provided by AP and Reuters.