CARTAGENA, Colombia - Colombia has beefed up security in Cartagena, a northern seaside city, for the upcoming summit of the Americas to be held on April 14-15.

In fact, 32 police agencies from 27 countries are throwing their weight behind the beefed-up security, as the city is welcoming 33 heads of state and government for the sixth Summit of the Americas under the theme of "Connecting the Americas: Partners for Prosperity."

Official figures show that a total of 7,680 officers, 400 vehicles with GPS, 300 video cameras, 36 radioactive detectors, six explosion-proof robots and 20 intelligent patrols with 85 special devices have been put on guard against any potential threat.

Colombia is facing both guerrilla and drug wars, and the Revolutionary Armed Forces of Colombia rebels have adopted a hit-and-run strategy.

The Colombian authorities said US President Barack Obama is scheduled to arrive in Cartagena on Friday afternoon.

Calling the Western Hemisphere an increasingly "prosperous and peaceful" region, White House officials said Obama aims to continue his efforts to promote US businesses and boost trade and investment across the region.

Venezuelan President Hugo Chavez is also scheduled to arrive here on Friday, though speculation has been rife about Chavez's absence, as he has spent the last few days in Cuba undergoing a third session of radiation treatment for his cancer.

Absent from the summit will be Cuban leader Raul Castro as Cuba is not invited due to the opposition from the United States, and Ecuadorian President Rafael Correa, who chose not to attend to show his displeasure at Cuba's exclusion.