GROZNY — Two suicide bombers on bicycles detonated explosives in Grozny on Friday, killing at least four police officers and a civilian in coordinated attacks, officials said.

"One suicide bomb was detonated four meters from a police car, killing two officers," Chechen Interior Minister Ruslan Alkhanov told reporters. "Two police died and one was injured in a second attack." Both attackers used bicycles, he said.

The use of bicycles would represent a change of tactics for insurgents in the North Caucasus, who have carried out suicide bombings by foot or using cars and trucks.

Blood and body parts could be seen near the charred remains of a bicycle and a police car at the site one of the explosions. Police blocked reporters from approaching the site of the other bomb.

Grozny has seen a series of bombings in recent months, ending years of relative calm in the city during a rebuilding campaign by President Ramzan Kadyrov. Friday's attacks come at the beginning of the Muslim holy month of Ramadan.

(Reuters, AP)