报警(bào jǐng) - to call the police, to report an emergency, to raise an alarm in Mandarin

出chū事shì了le，快kuài报bào警jǐng！

Something has happened, call the police quickly!

她tā马mǎ上shàng拿ná起qǐ电diàn话huà报bào警jǐng。

She picked up the phone and called the police at once.

如rú果guǒ遇yù到dào危wēi险xiǎn，请qǐng立lì刻kè报bào警jǐng。

If you are in danger, call the police immediately.

邻lín居jū听tīng到dào声shēng音yīn就jiù报bào警jǐng了le。

The neighbour heard the noise and called the police.

报bào警jǐng以yǐ后hòu，警jǐng察chá很hěn快kuài就jiù来lái了le。

After the police were called, they arrived very quickly.