Russian authorities found and defused a bomb in the southern Russian city of Rostov-on-Don on Saturday, foiling what was believed to be an attempted terrorist attack, officials said.
At about 4:45 am (0045 GMT), a cardboard box was discovered outside a police station in Rostov-on-Don, and on further examination it was discovered to contain a bomb, Russia's investigative committee said.
The box contained "a homemade explosive device consisting of a mobile phone, two detonators and incapacitating elements in the form of nails," the committee said in a statement.
A police source told the RIA-Novosti news agency that the explosive device contained a 1.5-litre bottle with an ammonia mix and aluminium powder. The Interfax news agency said it had been found by a policeman on patrol.
The bomb was successfully defused and authorities opened a investigation on charges of terrorism and unlawful preparation and use of explosives, the investigative committee said.
Russia has been on edge about militant attacks ever since a double suicide bombing in the Moscow metro killed 40 people last month.
A radical Islamist group based in Russia's volatile North Caucasus claimed responsibility for the metro bombing.
Rostov-on-Don is in southern Russia about 1,200 kilometres from Moscow but lies outside the North Caucasus, where bombings and attacks on police targets occur regularly.
{{/usCountry}}Rostov-on-Don is in southern Russia about 1,200 kilometres from Moscow but lies outside the North Caucasus, where bombings and attacks on police targets occur regularly.
{{/usCountry}}The city is due to host an EU-Russia summit next month.