Police in southern Germany used the system during an attack earlier this week by a lone gunman at a mall.

Now Switzerland’s federal police, Fedpol, is considering a system similar to that used by some states in Germany, 20 Minuten reported.

At present no such system is used in Switzerland.

Residents of Munich with a smart phone were sent a message during the attack telling them to avoid squares and streets in the area and warning them that public transport had been suspended.

The message was sent using the Katwarn system that sends a text in the event of an emergency or large-scale incident.

“We are currently evaluating a warning system,” Fedpol spokeswoman Anne-Florence Débois told the paper.

She could not say what form the warning system would take or when it would be introduced.

The Tages-Anzeiger quoted telecoms expert Ralf Beyeler as saying a text message alarm made sense.

In an emergency the federal authorities could instruct mobile service providers to send a text message to all mobile phones logged onto a network in the area, the expert said.

But this would depend on a functioning network.

“In an extreme situation, such as a terror attack, this could lead to problems as everyone would contact their loved ones and the network would be overloaded,” Beyeler said.

From a technical point of view Cell Broadcast technology, where providers send messages to all devices logged on to a mobile phone tower, was the best option, he said.

This system places a minimal burden on the mobile network and all users can be notified.

Another option was a warning app but this would need to be installed by users and would also require a network.