New Zealand police on Wednesday ruled out any link between a bomb found in Christchurch and mosque shootings in March which killed 50 Muslim worshippers.

Police and the military bomb squad swooped on a vacant lot just outside the city centre Tuesday finding “a suspected explosive device” and rounds of ammunition.

They said a 33-year-old man appeared in court Wednesday charged with possession of explosives, ammunition and offensive weapons.

“We are not seeking anyone else in relation to the incident,” detective inspector Corrie Parnell said in a statement.

“There are no known links between the 33-year-old man and the Christchurch attacks on March 15.”

Local media named the man as Jay Michael Harding-Reriti and said the charges included possession of a handheld improvised explosive device, powergel explosives and detonator cord.

They said he was remanded in custody until May 6 and further details of the case were suppressed at the request of police.

Christchurch remains on alert after the March attacks in which a self-styled white supremacist shot dead 50 people and injured another 39 in attacks on two mosques.

The gunman allegedly behind the mosque shootings, 28-year-old Australian Brenton Tarrant, is in a maximum-security prison in Auckland has been ordered to undergo psychiatric tests.