Colombia has heightened security ahead of President Alvaro Uribe's inauguration for his second term in office.

Tens of thousands of troops are patrolling the country, and sharp shooters will be perched on rooftops looking for security threats to Monday's events.

Several suspects have been detained as police try to prevent a repeat of an attack on the 2002 inauguration, when guerrillas from the Revolutionary Armed Forces of Colombia or FARC, launched mortars at Mr. Uribe. Twenty-one people in a nearby neighborhood were killed.

Mr. Uribe easily won the election in May, bolstered by his fight against the rebels. Officials say rebel attacks often increase ahead of elections and inaugurations.

Officials have blamed the FARC for a recent wave of attacks.