Washington ? Problems involving baggage screening machines and security checks for foreign travelers persist at airports, government watchdogs said Thursday.

Transportation Department Inspector General Kenneth Mead said some of the large machines many airports used to screen checked bags for explosives gave off too many false readings. He’s investigating to make sure the machines are functioning properly.

“We need to focus hard on the equipment,” Mead said.

Meanwhile, an audit by Justice Department Inspector General Glen A. Fine criticized the Immigration and Naturalization Service for failing to correct significant security deficiencies at airports.

The report, released Thursday, found airports remained vulnerable to illegal entries by foreign travelers; smuggling of aliens, drugs and other illegal substances; and escapes by people detained for questioning.

Fine said the INS had largely failed to put in place recommendations aimed at fixing problems first identified in a 1999 audit. These include badly located or inoperable surveillance cameras, inability to videotape interviews with detainees, alarms that don’t work and other security features never installed.

“We found that the INS had not even advised its own airport staff of the results of the prior audit,” the report said. “Significant and ongoing deficiencies continue to exist at INS airport inspection facilities.”

The Transportation Security Administration is responsible for overall security at commercial airports, but the INS has oversight of foreign travelers.

The TSA was created after the Sept. 11 attacks to take over airport security. Congress gave it until Jan. 1 to begin screening all checked bags at the nation’s 429 commercial airports.