Vladivostok: Police in Russia's far east stormed a building on Friday where four suspects in a rare string of attacks on police were holed up, leaving two dead and detaining the other two, officials and media reported.

Attacks on police are rare in Russia outside the turbulent Caucasus, where the Kremlin is battling an Islamist insurgency spawned by two post-Soviet wars against Chechen rebels and law enforcement authorities are targeted in near-daily attacks.

The suspected gang's motives were murky, but there has been speculation of anger over police corruption and abuse — a hot-button topic in Russia, where President Dmitry Medvedev is struggling to reform a police force tainted by scandals.

The standoff, punctuated by gunfire, followed a days-long hunt for a handful of men accused in the fatal May 27 shooting of a policeman, as well as two other attacks that injured three other police officers and the torching of a police station.

Siege

Two of the suspects — men aged 21 and 23 — died in the five-hour siege of a building in the city of Ussuriysk, Russian news agencies cited provincial investigative official Avrora Rimskaya as saying.

She said it was unclear whether they had been killed by police bullets or took their own lives, Itar-Tass reported.

Two others surrendered, one early in the standoff, Rimskaya said.

At least one police officer was injured, she said in televised comments.

She said those captured could face life in prison. Police said two of a total of six suspects were detained this week.

Rimskaya said reports that a former paratrooper who served in the wars in Chechnya, Roman Muromtsev, 32, was the gang's leader, were untrue. "Muromtsev has nothing to do with this gang," she said.