A satellite phone, which was switched on during the recent visit of Prime Minister Manmohan Singh and UPA Chairperson Sonia Gandhi to the city, caused a scare among security agencies which were on maximum alert, police said on Monday.

However, the phone was tracked to three Israeli tourists, all girls, they said.

The prime minister, Gandhi and a host of other national leaders were in the city on March 13 for the inauguration of the new Tamil Nadu Assembly complex.

There was “lot of confusion” after police headquarters picked up signals from the satellite phone during the function, prompting the police to launch a hunt to track the users. The police, who zeroed in on the girls, took the phone into their possession till the prime minister left the city, they said.

During questioning, the trio were found to be “innocent” and they were let off with a warning not to use the satellite phone during their stay in the country, police said.

Unprecedented security arrangements had been made for the visit of the VVIPs, which also included Chief Ministers of Karnataka and Andhra Pradesh B.S. Yeddyurappa and K. Rosiah respectively. The police had even barred fishermen in the faraway district of Ramanathapuram from venturing out into the sea during the visit citing security reason.