German police early today closed off the front access to Angela Merkel's chancellery building after the arrival of a suspicious mail package, which was being checked by explosives experts.

Television footage showed four yellow plastic postal crates in the snow outside the gates of the compound, surrounded by police tape. "Arriving mail is routinely checked, and today we found something suspicious," a federal police spokesman told AFP.

"The area has been closed off and specialists of the Berlin and federal police are taking a close look."

The operations of the chancellery were not affected since there are other entrance ways, and Merkel's top ministers started a morning cabinet session as usual, police said.