By TIM JOHNSON
 Herald Staff Writer

 BOGOTA, Colombia -- President Andres Pastrana sacked an army brigadier
 general on Thursday, nearly two weeks after the officer failed to halt a rampage by
 right-wing militias in his area of command.

 The firing of Brig. Gen. Alberto Bravo Silva marked the second time this year
 Pastrana has cashiered senior military commanders for human rights reasons.

 Pastrana gave no reason for the firing. A decree from the presidential palace said
 simply that Bravo Silva had been sent into retirement.

 But human rights monitors say the Pastrana administration is clearly responding
 to U.S. demands that Colombia clean up the military of accused rights abusers
 before vast new assistance for the beleaguered armed forces is released.

 ``It's a very welcome sign,'' said Robin Kirk of Human Rights Watch. ``The
 government acted in a speedy manner.''

 Private militias swept into a coca-growing area along the northeast border with
 Venezuela, near the village of Catatumbo, and killed at least 36 people on Aug.
 21, while the army's 5th Brigade under Bravo Silva did nothing to stop them.
 Dozens of other peasants have been killed in the same region since early June.

 The massacre outraged local human rights groups and a United Nations
 monitoring commission, which later said that they had warned Bravo Silva about
 paramilitary threats to civilians in the area but he had failed to act.

 ``Bravo is an important general. We're talking about someone who was in line to
 become a top commander in the Colombian military,'' Kirk said.

 In April, Pastrana cashiered two army generals, Rito Alejo del Rio and Fernando
 Millan, amid charges they had helped militia death squads in brutal ``cleansing''
 campaigns against suspected leftists.

 Colombia is seeking new U.S. assistance for its armed forces, which are locked
 in battle with two leftist insurgencies that roam through nearly half the country. In
 July, Defense Minister Luis Fernando Ramirez asked Washington for $500 million
 in aid over the next two years, a request that U.S. officials said they would
 consider seriously. U.S. drug czar Barry McCaffrey also has suggested Colombia
 should receive as much as nearly $600 million in increased U.S. aid, much of it
 for the military.

 Pastrana's quick action on Bravo Silva should be seen in light of the aid requests,
 said Winifred Tate of the Washington Office on Latin America, a rights and
 democracy advocacy group.

 ``They are aware of the debates coming up before the U.S. Congress about
 military aid and they are very interested in portraying the army as being reformed,''
 she said.

 Even Bravo Silva, sounding unperturbed by his firing, told local Radionet that
 Colombia should do whatever is necessary to beef up the army.

 ``In current circumstances, the defeat of the guerrillas can come only with the
 strong growth of the armed forces,'' he said.
 e-mail: timjohnson@herald.com