WELLINGTON, March 22 (Xinhua) -- The New Zealand Police are investigating death threats sent to Prime Minister Jacinda Ardern on social media, local media reported on Friday.

A Twitter post containing a photo of a gun and caption "You are next" was sent to the prime minister.

The post had been up for more than 48 hours before the sender's Twitter account was suspended after it was reported by various people.

The suspended account contained anti-Islamic contents and white supremacist hate speeches, according to the report.

Terror attacks hit New zealand's Christchurch last Friday, killing at least 50 people and injuring 50 others.

In the aftermath of the terror attacks, Prime Minister Jacinda Ardern vowed to change the gun law in the country.

Ardern announced on Thursday that military style semi-automatic weapons and assault rifles are to be banned in New Zealand.