Russia is to beef up security around its embassies following the killing of its ambassador to Turkey in a gallery in broad daylight.

Andrei Karlov was shot dead as he gave a speech in the Turkish capital of Ankara on Monday afternoon.

He was killed by Mevlut Mert Altintas, 22, a Turkish policeman, who expressed anger at Russia's involvement in the Syrian city of Aleppo before he too was shot dead.

Read more: Russian Consul General in Edinburgh pays tribute to 'dear friend cowardly gunned in the back'

The killing followed days of protests in Turkey over Russia's support for the Syrian government and its role in the siege of Aleppo.

Yesterday Mr Karlov’s widow Marina went to Esenboga aiport in Ankara to see off her husband’s coffin on a special military flight to Moscow.

Reports in the Turkish press suggest that the killer used his police identification to avoid metal detectors at the entrance to the gallery where the attack took place.

There were also reports that police had detained seven people in a series of overnight raids, including Altintas’s parents, sister and three other relatives.

Sergei Lavrov, the Russian foreign minister, thanked the Turkish authorities for their “instantaneous response” and neither that country should not allow "any concessions to terrorists”.

"This tragedy forces all of us to fight more decisively against terrorism," Mr Lavrov he said as he met Turkish Foreign Affairs minister Mevlut Cavusoglu in Moscow.

The killing was carried out at a pivotal moment for Russia and Turkish relations.

Read more: Russian Consul General in Edinburgh pays tribute to 'dear friend cowardly gunned in the back'

Russia has backed Bashar al-Assad’s Syrian government while Turkey has backed anti-Assad rebels throughout the war in the country.

However, Turkey did not intervene in the recent battle for Aleppo after the Turkish President Recep Tayypi Erdogan and Russian President Vladimir Putin agreed to set aside their differences.

The Russians hope that a more secure deal on Syria could allow them to become the pre-eminent power in the Middle East.

Both leaders suggested that Mr Karlov’s murder was an attempted attack on the fragile alliance between the two countries.

Mr Putin and Mr Erdogan also agreed to conduct a joint investigation into the killing, in a bid to discover if Altintas was acting alone or as part of a wider network.

He has been linked to the failed coup against Mr Erdogan over the summer.

Turkish officials have also suggested he may be linked to Fethullah Gulen, a US-based anti-Erdogan cleric.

A group of 18 Russian investigators and foreign ministry officials have been sent to Ankara to investigate the killing.

Reports suggests the killing was planned.

Altintas had taken leave from work on medical grounds and booked himself into a hotel near the exhibition centre, according to the Turkish newspaper Hurriyet.

Police in Ankara have also detained a man who fired shots in front of the US embassy hours just after the killing.

No-one was hurt in the incident.

Read more: Russian Consul General in Edinburgh pays tribute to 'dear friend cowardly gunned in the back'

But the man reportedly fired a number of shots in the air before he was overpowered.

The US Embassy said that its embassies in Ankara, Istanbul and the southern city of Adana would be "closed for normal operations on Tuesday".

Russian deputy foreign minister Oleg Syromolotov also warned Russians against travelling to Turkey, citing attacks that have hit the country over the past 18 months.

Meanwhile, Swiss police said they have found no sign of any radical Islamist or far-right motive by a gunman who killed himself after a shooting at a Zurich mosque which left three worshippers wounded.

Police chief Christiane Lentjes Meili said that investigations were continuing in connection with the 24-year-old Swiss man who carried out the shootings, also on Monday.

She told reporters: "There's no indication of any kind of terrorist connection to (the Islamic State group) or any Islamic radicalisation of the suspect. "

Ms Lentjes Meili said that police had uncovered that the gunman, who was not named, had also recently stabbed an acquaintance to death.