The Transportation Security Administration (TSA) will take over security checks of passengers and baggage at city heliports, days after police were warned that al-Qaida had considered using tourist helicopters in possible attack on New York City.

The federal government will also check names of passengers against lists of terrorist suspects and conduct background checks on helicopter tour operators' employees, said a TSA directive issued late Monday.

Tour operators will be required to appoint an on-call security coordinator to answer security questions from the government, the directive said.

The TSA directive, which applies only to New York City helipads, follows two nationwide Federaal Bureau of Investigation bulletins sent late last week to 18,000 police officers and other government officials, concerning the targeting of helicopters by al-Qaida.

"We've had people on the ground for the past couple of weeks to determine what mix of personnel and equipment will be needed," said TSA spokesman Mark Hatfield. "These will be personnel in TSA uniform."

New York Mayor Michael Bloomberg downplayed the report on terrorists' plan to use helicopters as weapons Monday, saying they indicated no fresh threat to the city.

"This is nothing new, that they discover that an aircraft can be used as a weapon," the mayor said. Security measures including metal detectors and ID checks have been in place at New York helicopters since after the Sept. 11 attacks and no major changes are anticipated, he said.

The TSA indicated that their directive was not directly connected to intelligence information coming from abroad.

"The intelligence streams have contributed to this action but it is only one track," Hatfield said. "we have an ongoing risk assessment that has pointed us into this direction as well."