Milquet, responding to criticism from the center-left Reformist Movement over the move, said the government is confident tight security measures introduced at Belgian international railway stations Aug. 5 could be safely reduced.
Security was stepped up in the wake of the closure of 19 U.S. embassies and consulates in the Middle East and Africa following the interception of intelligence that al-Qaida was planning a major terrorist attack against U.S. and Western targets.
The security measures were eased Friday.
Milquet said the move was justified by a downward revaluation of the terrorist threat by the Coordinating Body for Threat Analysis but added security had nevertheless been strengthened in some "strategic locations until further notice," the Belgian news agency BELGA reported.
The statement came only hours after Milquet was challenged by Parliamentarian Denis Ducarme, a member of the French-speaking liberal party the Reformist Movement, which is part of Belgium's governing coalition.
Ducarme said he wanted a "reassessment" of the decision to reduce the police presence at the train stations, saying it would be "useful for the interior minister to confirm (with the U.S. National Security Agency) that this exercise is quite justified.
"I'm surprised we have changed tack in just two or three weeks," Ducarme told BELGA, noting that, unlike Belgium, Germany and the Czech Republic have decided to step up security measures against terrorism risks.
Ducarme also claimed that while security levels at Brussels high-speed train stations were increased, those in the French-speaking southern Wallonia region weren't.
Milquet, however, denied any difference in her Tuesday statement.
"The measures are identical for all lines," she said.
Louis Maraite, spokesman for the Belgian national railway operator SNCB, confirmed police presence was being reduced at stations despite a report by the German newspaper Bild that Al-Qaida was planning attacks on high-speed trains in Europe.
Maraite said the security situation was returned to normal after consultations with the authorities, the police and Securail, the Belgian railway security force.
German authorities, meanwhile, indicated they would monitor lines used by the German high-speed ICE trains and their stations for two weeks, while deploying a series of discrete additional measures, such as plainclothes police officers.
Bild reported the attacks could take the form of acts of sabotage on the tracks and tunnels and bombs on trains. The newspaper said the information came from the NSA, which has reportedly intercepted a telephone conversation this month between senior Al-Qaida figures.
The report prompted no additional security measures in the neighboring Netherlands, a spokesman for the National Coordinator for Counterterrorism and Security told the Dutch daily De Telegraaf.
There is no concrete information that Dutch trains are being targeted, he said, adding, "It's old information, which has been known to us."