BOGOTA, Colombia - Judicial authorities yesterday ordered arrests of 20 politicians and business leaders, including five congressmen, on criminal conspiracy charges for signing a 2001 pact with illegal right-wing militias.

All are accused of benefiting - at the ballot box or otherwise - from close ties to the paramilitaries, which committed contemporary Colombia's most-brutal massacres and stole land from tens of thousands of peasants.

It was the latest shock wave in a scandal that has badly marred President Alvaro Uribe's credibility because nearly all those implicated are his political allies, although the second-term president enjoys broad popularity for making Colombia's cities safer than they had been.

The nation's chief prosecutor, Mario Iguaran, rejected claims by some of the pact's signatories that they signed under duress.

"They willingly and freely participated in the meeting," he told reporters.

The Supreme Court has ordered the arrests of 14 members of Colombia's 270-member Congress since the so-called para-politico scandal broke last November. As of midday yesterday, only two remained at large.

All but one of the implicated congressmen are allies of Uribe, whose foreign minister resigned in February, after her senator brother was jailed in the scandal.

Uribe's former spy chief is also under investigation, and opposition leaders claim Uribe himself let the militias gain strength when he was a provincial governor in the mid-1990s.

Last week, Vice President Francisco Santos predicted as many as 30 lawmakers will end up in jail in the scandal, which has prompted the new Democratic leadership in the U.S. Congress to question whether Uribe's government merits such high levels of military aid without greater scrutiny of its human-rights record.

Colombia receives more than $600 million in mostly military aid annually for counterinsurgency and anti-narcotics.

Most has gone to strengthen military and police efforts that in the early 2000s put leftist rebels on the defensive even as the right-wing paramilitaries gained clout, infiltrated government and became major drug traffickers.

Among those arrested yesterday was Eleonora Pineda, a former congresswoman who served as a go-between with paramilitary bosses before they surrendered under a 2004 peace pact, which limits jail terms to eight years for warlords who confess to their crimes.

Pineda was kicked out of a pro-Uribe political party last year because of her paramilitary ties.

She and the 30 other signatories pledged in the June 2001 pact to "rebuild the homeland" along with the paramilitary United Self-Defense Forces of Colombia.

Four paramilitary warlords signed, among them Salvatore Mancuso, who would later state publicly that the paramilitaries owned 35 percent of Colombia's Congress.