Paris beefs up security for Christmas celebration

French authorities on Tuesday said security at religious sites in Paris are strengthened to preserve calm during Christmas festivities as terrorism menaces remain high.

An adapted security plan will be implemented to ensure the security of the traditional celebrations that will take place on Tuesday and Wednesday at Christian religious sites in the capital, said Paris police prefecture in a statement.

"In consultation with the responsible for places of worship, appropriate measures to each situation will be taken and specific monitoring will be put in place at the time of entrances and exits of worshipers," it added.

"Terrorist threat remains high at the end of the year," warned Nicolas Lerner, director general of General Directorate for Internal Security (DGSI) when speaking to France info radio on Monday. He said four terrorist attacks have been foiled so far this year.

France has seen several attacks on home soil claimed by the Islamic State group, with the deadliest one occurring in Paris in November 2015, killing 130 people.