India said Friday that a visit by Japanese Prime Minister Shinzo Abe had been postponed, after days of violent protests at a northeastern city where a summit with Prime Minister Narendra Modi had been planned.

"Both sides have decided to defer the visit to a mutually convenient date in the near future," Indian foreign ministry spokesman Raveesh Kumar said in a statement.

He gave no further details and did not give the reason for the postponement of the trip, which both sides had said would take place from Sunday to Tuesday.

The location for the discussions had not been revealed.

But Indian press reports had said they would happen in the northeastern Indian city of Guwahati in Assam state - the epicentre of recent demonstrations that on Thursday saw two protesters shot dead.

Thousands of demonstrators were on Friday gearing up for another day of protests, after the Indian parliament passed contentious new citizenship legislation this week.

Many in the far-flung northeast believe the government's new legislation will give citizenship to immigrants from neighbouring Bangladesh.

An AFP reporter in Guwahati said that dozens of posters for the India-Japan summit were lying on the ground after protesters tore them down.

Japan's Kyodo news agency also reported Abe's visit was cancelled because of the worsening security situation, citing the country's chief cabinet secretary.

Modi and Abe had been slated to visit a new Peace Museum in Manipur - another northeastern state - dedicated to the tens of thousands of soldiers, mostly Japanese, who died at the WWII Battle of Imphal between Japanese and Allied forces.