By the BBC's Nick Miles in Mexico City

The Mexican Government is basking in the news of last Saturday's arrest of Benjamin Arellano Felix, the head of Mexico's most powerful drugs cartel.

You can cut off the heads of an organisation, but they will always grow back

Luis Astorga National Autonomous University

He allegedly led the cartel for 20 years, based in the town of Tijuana on the border with the United States, developing a maze of contacts with suppliers of cocaine and heroin in Colombia.

The organisation he set up is believed to have a turnover of billions of dollars a year, supplying up to half of the cocaine entering the US every year.

Mr Arellano Felix was on the list of America's 10 most wanted criminals.

Following his arrest, the head of the US Drug Enforcement Agency, Asa Hutchinson, called for his extradition to face cocaine smuggling and money laundering charges.

Body blow

The arrest and the confirmation of the death of his brother, Ramon, who ruthlessly ran the security side of the operation, led the Mexican attorney general's office to claim that "we have taken the cartel to pieces".

Certainly, with arrests of other key figures made in recent months, the latest developments mean that the Tijuana operation has been dealt a body blow.

A tunnel used to transport drugs to the US from Mexico

But there is a growing realisation that, as in the past, when a vacuum appears at the top of a drugs gang, a bloody turf war follows.

"You can cut off the heads of an organisation, but they will always grow back," said Luis Astorga, a specialist in the drugs trade at Mexico City's National Autonomous University.

"The business carries on because there are always people from within or outside the cartel that are waiting to take over."

Violent cartel wars

The history of Mexico's drugs cartels backs this up.

Years of violent struggles followed the arrest in 1989 of Miguel Angel Felix, then head of the Mexican cocaine and heroin trade.

The logical scenario is that the cartels from Sinaloa and the Gulf of Mexico now try to break into Tijuana

Jesus Blancornelas Editor of Zeta magazine

The Arellano Felix brothers came out on top, asserting their control over the Tijuana cartel.

But struggles between them and traffickers based in the state of Sinaloa continued for years.

A shootout in a nightclub in November 1992 left eight people dead.

Another incident six months later left a death toll of seven, including a Roman Catholic cardinal - apparently the victim of mistaken identity.

Tit-for-tat killings continued, culminating in the assassination of the head of the Sinaloa cartel, Amado Carrillo Fuentes, in 1994.

He was shot dead hours after undergoing plastic surgery.

Hundreds of other lower ranking members of opposing gangs died in the years that followed.

Possible heirs

The killings seemed to die down during the late 1990s as areas of control became more delineated, but now that uneasy status quo has been upset.

Benjamin Arellano Felix: One of America's top 10 most wanted

A number of names are already being put forward to take over the Arellano Felix cartel.

"The logical scenario is that the cartels from Sinaloa and the Gulf of Mexico now try to break into Tijuana," said Jesus Blancornelas, the editor of the Tijuana based magazine Zeta.

"There could be any number of candidates for that. Ismael Zambada, head of the Sinaloa cartel, which has already started encroaching on the Tijuana patch, is one.

"And don't forget there are a number of other members of the Arellano Felix family actively involved in the trade as well. They will want to assert their authority too," he said.

Government 'prepared'

The potential for a bloody war for control has not been lost on the Mexican authorities.

"The security forces are prepared to confront any upsurge in drug-related violence that might emerge," said the Defence Minister, General Clemente Vega.

These operations work like any kind of multinational company - if there is a demand to fulfil, then normal production will start again as soon as possible

Luis Astorga

"I can assure society, I can assure Mexico that we are prepared," he said.

Just what effect the leadership struggle will have on the supply of drugs is unclear.

"There may be a short-term drop," said National Autonomous University's Luis Astorga.

"But these operations work like any kind of multinational company. If there is a demand to fulfil, then normal production will start again as soon as possible.

"And the demand is still there - there's no sign that narcotics consumption in the United States is about to fall away," he said.

Certainly Mexico can rightly claim to deserve the praise it has been receiving from the United States for its efforts to fight the drugs trade.

As recently as the mid 1990s, corruption among the police, army and local politicians provided a protective shield for the drug smugglers to work with impunity.

Now that culture appears to be on the wane. But even if the successes against the drugs barons continue, the vast profits to be made in the trade will mean there will always be new candidates waiting in the wings to take over.