A clash between military units in Guinea-Bissau exposed the tangled affairs of this unstable nation where a powerful army and state are intertwined and cocaine cartels have deep roots.

When a group of soldiers attacked the country's army headquarters early Monday they said they were merely seeking a pay rise.

However army chief General Antonio Indjai -- who overthrew his predecessor last year -- said the men had seized weapons from the armoury and the regime was quick to brand the incident a coup attempt.

"It was an attempt to make political and military changes," agreed Bissau researcher Mamadu Jao.

Controversial navy chief Rear-Admiral Jose Americo Bubo Na Tchuto was swiftly rounded up as the brains behind the operation along with several other soldiers and political officials.

Some observers put Monday's mutiny down to a falling out between Indjai and Bubo Na Tchuto - who once fled the country after being implicated in a 2008 coup bid and has been dubbed a drug kingpin by the United States.

Na Tchuto was reinstated to widespread consternation in 2010 shortly after Indjai ousted his predecessor in a mutiny in which he held hostage Prime Minister Carlos Gomes Junior.

Power plays, score-settling and coups are nothing new in this former Portuguese colony which has remained highly unstable and impoverished since independence in 1974.

In 2009 President Joao Bernardo Vieira was assassinated in an apparent revenge attack by soldiers a few hours after the army chief was killed in a bomb attack.

"It is always difficult to distinguish between politics and the military" in Guinea-Bissau, said Vincent Foucher, a researcher with the International Crisis Group in Dakar.

"However we lean towards a political dimension because there is at least one lawmaker who is seen as linked to the soldiers" who carried out the attack.

This parliamentarian, Roberto Cacheu, is a member of the ruling party reported to be opposed to Carlos Gomes, and is being targeted by police in search operations which have already left two people dead.

Foucher noted that many of those being sought are considered allies of assassinated leader Vieira.

The waters are further muddied by the cold-blooded execution of a senior policeman, Yaya Dabo, outside a police station where he had gone to turn himself in for his role in Monday's attack.

Goverment said guards on duty at the police station opened fire on him as they held him "responsible for the shooting of one of their comrades" the night before.

However Dabo was also the brother of former territorial administration minister Baciro Dabo, killed in 2009 three months after his close ally Vieira, whom he was considered a strong contender to replace as president.

As the lines are blurred between army and state, power struggles play out against the backdrop of a booming cocaine trade which has seen some observers label Guinea-Bissau, with its weak institutions, a narco-state.

The UN drug agency's (UNODC) special report on Guinea-Bissau in 2008 noted repeated allegations that "high ranking officials in government and the military are complicit in drug trafficking."

Guinea-Bissau, with its porous coasts and an archipelago of islands where airstrips can be set up, has allowed Latin American drug lords to act with impunity, and political instability is good for the drug trade.

According to UNDOC, some 27 percent of the cocaine consumed annually in Europe passes through West Africa with a street value of $1.8 billion and Guinea-Bissau is the worst culprit.

The country has made recent gains, setting up an anti-drug agency in February as a bid to combat trafficking, however institutions remain extremely weak and much-needed army reform the country's greatest challenge.

The government needs to reduce army numbers from 10,000 to 3,400, according to military estimates, a solution which sparks "tension and concern among some soldiers", according to Foucher.

"In Guinea-Bissau the army occupies a central place in political life: it is the spinal column of the country and it is the army which plays practically all roles and distributes them simultaneously," said Senegalese analyst Babacar Justin Ndiaye.

"The state, the ruling party, the army, they are all tangled up and in constant competition."