Kyiv warns Russia as Moscow skyscraper hit in second drone attack

Several drones were shot down overnight on Monday, he said, but "one flew into the same tower at the Moskva City complex" that was targeted on Sunday.

Russia's defence ministry blamed Ukraine for the latest attack.

Kyiv did not comment on responsibility but warned Russia that the conflict could soon move to its territory.

Russia sees room for diplomacy

Vladimir Chizhov said Moscow had no intention of invading anybody, but warned it was important not to provoke Russia into changing its mind.

It comes after a flurry of diplomatic activity on Monday and Tuesday.

Russia has repeatedly denied any plans to invade Ukraine.

But with well over 100,000 troops massed near the Ukrainian border, some Western countries including the US have warned that a Russian attack could come at any time.

Moscow could 'defend' Russia-backed rebels

Russian-backed separatist rebels and Ukrainian troops have been clashing in the east of the country.

Russia has also been building up troops on the border with Ukraine.

The official, Dmitry Kozak, said that Russian forces could intervene to "defend" its citizens.

"Everything depends on the scale of the conflagration," he said.

He also warned that an escalation could mark the "beginning of the end" for Ukraine - "not a shot in the leg, but in the face".

The United States and Germany have both expressed concern at the increase in tensions.

Russian opposition leader Alexei Navalny detained on arrival in Moscow

He flew from Berlin to Moscow, arriving in Russia for the first time since he was nearly killed by a nerve agent attack.

The activist says the authorities were behind the attempt on his life, an allegation backed up by investigative journalists but denied by the Kremlin.

Russia's FSIN prison authority confirmed that officers had detained him, the Interfax news agency reported.

Metal barriers were erected inside the airport, Vnukovo, and Russian media reported that several activists - including key Navalny ally Lyubov Sobol - had been detained there.

Nearly 1400 people detained in Moscow protest; largest in decade

OVD-Info said the number of the detentions it logged for Saturday's protest reached 1,373 by early Sunday. The group has monitored arrests since 2011.

Russian police violently dispersed thousands of people who thronged Moscow streets on Saturday to protest election authorities for disqualifying independent candidates from the September 8 election for the Moscow city council.

Several protesters reported broken limbs and head injuries. Police justified their response by saying the rally was not sanctioned by authorities.

Duterte declares martial law in Mindanao amid clashes

ISIS' media wing, Amaq Agency, put out a statement announcing that "fighters of the Islamic State launch a wide-scale offensive on positions of Philippine troops in the city of Marawi."

Speaking from Moscow, Philippines Foreign Secretary Alan Peter Cayetano said that the violence in Mindanao, one of the Philippines' southernmost islands, was Duterte's priority, despite the high-profile visit to Moscow and St. Petersburg.

"(The Russians) understand that the security of the Filipino people, especially in Marawi and in Mindanao, is a priority," Cayetano said.

NATO chief: Russian jets in Turkish airspace no accident

Turkey's military, meanwhile, said more of its jets patrolling the border with Syria were placed in a radar lock by Russian planes and surface-to-air missile systems.

In Syria, Russian warplanes reportedly continued pounding targets in the country, where the Kremlin has come to the aid of beleaguered ally President Bashar Assad.

Moldovan police chief briefly detained at Moscow airport

Interim police chief Gheorghe Cavaliuc was stopped by Russian border police Tuesday and held at Domodedovo airport. He said he was initially informed there was a problem with his passport and later told he resembled a wanted criminal.

Cavaliuc was freed after three hours. He said he believed his detention was connected to his work, saying "I have researched a lot of international organized crime groups."

Helicopter-seaplane collision kills 9 in Russia

The Armenian Embassy said four citizens of Armenia, including two children, were among the dead. Russian Channel One state television said one of its journalists also was killed.

The Cessna 206 and Robinson 44 helicopter collided over the Istra reservoir Saturday night. By Monday morning, investigators said divers had recovered eight bodies, while the search for the ninth victim was continuing.

The federal Investigative Committee said the accident appeared to have been caused by pilot error.