At least 9 killed in eastern Ukraine rush hour shelling amid conflicting arrest reports (VIDEO)

At least nine people were killed and up to 20 injured in a shelling in Donetsk on Thursday morning. In the wake of the attack, conflicting reports emerged over the arrests of what local authorities call a 'covert group.'

Residents of Donetsk’s Leninsky district heard shelling at about 08:30 local time, media report. Windows in the buildings near a tram stop were blown out. Locals say they believed their district to be “a quiet place” and were shocked by the “tragedy that happened when people were heading to work.

A trolleybus was also hit, and eye-witnesses said there were victims inside, as well as bodies lying at the stop, local news outlets said. Conflicting reports, citing medical sources, indicate there may have been up to 13 deaths.

“A covert group has been operating, they have been arrested now. No more comments,” the defense minister of the self-proclaimed Donetsk People's Republic Vladimir Kononov told Gazeta.Ru newspaper.

The authorities of the self-proclaimed republic also say the shelling was carried with mortars, RIA-Novosti reported.

“Our officers were at the scene, according to the preliminary information, the shelling was conducted with mortars from one of the nearby districts. It appears that two bombs fell on the stop,” said a spokesperson for the DPR Security Ministry.

“The self-defense forces shortly thereafter arrested a covert group of Ukrainian security forces not far from the scene, at the moment it is being verified whether they were involved in the shelling,” the spokesperson added.

The deputy speaker of the DPR parliament, Denis Pushilin, told RIA-Novosti that the investigation is ongoing and that “the shelling was supposedly conducted from a minibus or a dustbin lorry.”

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Later on Thursday, local authorities denied previous reports of a "covert team" having been arrested in connection with the attack.

I want to rebut reports that have been widely published in the media that a covert group has been allegedly detained in connection with the Donetsk tragedy... the defense ministry has not said that. I can confirm what he [the minister] did say: that covert forces multiply, are being eliminated and neutralized. But I did not say that it was that particular group that had conducted it [the Thursday shelling],” Eduard Basurin, of local anti-government forces told journalists, as quoted by RIA Novosti news agency.

The self-proclaimed republic’s authorities also blamed Kiev’s forces for over a dozen violations of cease-fire agreements over the course of the day, Interfax reported. 19 violations were committed across Thursday, Basurin said, adding that civilian facilities, such as a kindergarten and a hospital have come under attack.

The OSCE has sent a group of its experts to the scene of the shelling in Donetsk to collect information, spokesman for the organization’s special monitoring mission to Ukraine Michael Bociurkiw told RIA-Novosti.

“Yes, we are aware [of what happened]. We have sent our patrol group to evaluate the situation. Taking into consideration the security situation, we are to present our assessment in the nearest future,” Bociurkiw said.

The OSCE special mission to Ukraine has called for an immediate ceasefire in the Donbas region and military disengagement after the Donetsk tragedy, a spokesperson for the mission told RIA-Novosti.

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DPR’s Emergency Ministry told RIA-Novosti: “As the shelling hit the “Kuprina street” stop, nine people were killed, including a driver of a car that was parked nearby. The car caught fire... Another ten people were injured and taken to hospitals.”

Screenshot from RT video

Russia will raise the issue of the deadly Donetsk shelling on Thursday at a session of the OSCE Permanent Council, the country’s permanent representative said, as cited by RIA-Novosti.

“We are stunned by a new monstrous offence in Donetsk … that we regard as a crime against humanity, a barbaric provocation, aimed at disruption of the efforts to regulate the Ukrainian crisis peacefully,” Russia’s Foreign Minister Sergey Lavrov said in a statement. “It becomes evident that 'the party of war' in Kiev and its foreign patrons won’t be stopped by loss of life.”

Lavrov also called for an immediate investigation into the incident, which would involve the OSCE mission. “Everything has to be done to stop Kiev’s shelling of cities of south-eastern Ukraine,” he said.

Ukrainian Prime Minister Arseniy Yatsenyuk said that Russia bears responsibility for the tragedy, blaming rebels for the deaths of civilians in Donetsk, Reuters reported.

“Today Russian terrorists again committed a terrible act against humanity. Russia bears responsibility for this,” he said at a ceremony to mark Unity Day in Kiev.

The shelling comes shortly after the meeting on Wednesday of the foreign ministers of Russia, Ukraine, Germany and France in Berlin, where they tried to progress with a solution to the Ukrainian crisis.

READ MORE: 12 killed, 13 injured as shell hits bus near Donetsk, E. Ukraine

On January 13, twelve people died and 13 more were injured as a bus was shelled in the eastern Donetsk region, Ukraine’s Interior Ministry said. Denis Pushilin, Donetsk People’s Republic representative at Minsk talks, said the attack may have been staged by Kiev.

The incident took place near a Ukrainian military checkpoint near the town of Volnovakha, the spokesman for the Interior Ministry in the Donetsk region, Vyacheslav Ambroskin, said.

Initially, 10 people were killed in the shelling. A woman reportedly died in hospital later in the day, according to the Donetsk regional administration which cited health officials. The regional administration also reported that 18 people had been injured.