Stephen Harper has returned to Kiev just as the war in eastern Ukraine erupts again with hundreds of explosions over two days that threaten to shatter an already tattered ceasefire in the region.

He brought with him members of Canada's Ukrainian diaspora who are raising funds and bringing gear to help their ancestral home fight a conflict that shows no signs of abating.

These include a Canadian representative of Army SOS which recently bought a $30,000 radio direction finder which can help the Ukrainians locate the source of enemy radio broadcasts.

Story continues below advertisement

The Ukraine capital's Independence Square is no longer crowded with the tents of Maidan protestors who led the ouster of pro-Russian president Viktor Yanukovich in early 2014.

But the ensuing war with Russian-backed rebels, which has claimed more than 6,400 lives in the last 15 months, still hangs over the country. Ukraine reinstated military conscription in 2014 to deal with the rebels and this year it's calling up tens of thousands of young people to join the fight.

An official with the Organization for Security and Cooperation in Europe, which is trying to monitor the conflict, said the tempo of the renewed violence is remarkable.

"This is something we've not seen before," Michael Bociurkiw told reporters.

"We do see a slight widening of the conflict area and we do see flaring up in hot spots that have been quiet for some time."

As Mr. Harper toured a police academy Saturday, the sounds of war continued to rock rebel-controlled Donetsk some 600 kilometres to the east.

Mr. Bociurkiw said this followed intense shelling on Friday when about 100 explosions were heard in Donetsk as well as heavy fighting around midnight local time on June 4 when around 500 explosions occurred.

Story continues below advertisement

"We've not seen or heard that type of intensity before."

He said the OSCE's drone that was trying to monitor the conflict saw a concentration of heavy weaponry coming from rebel-controlled areas and moving westward. Both sides have now moved these type of armaments into the heart of the conflict – a violation of the February Minsk ceasefire deal.

The OSCE drone's detection capacity was eventually jammed by what Mr. Bociurkiw said was military-grade counter-surveillance technology.

"This is not the type of technology you find in a hardware store."

Richard Hareychuk, a Ukrainian Canadian who travelled to Kiev with Mr. Harper, said Army SOS in Canada alone has raised $150,000 to help Ukraine's soldiers.

He's in Kiev to promote a new proposal to raise cash for the Ukrainian military.

Story continues below advertisement

Mr. Hareychuk, an optometrist by trade, is selling the idea of a landing tax to be levied on arrivals in Ukraine to help fund the fight against Russian-backed rebels.

His organization doesn't buy weapons for Ukraine but it tries to offer Kiev's forces the gear that can give them an edge on the battlefield.

"It's beyond our comfort zone. We come up to a point but we have to abide by the laws of the land."

He says Canadian export law forbids the shipment of not only weapons but also high-grade technology.

"Even thermal vision goggles are limited. Up to a certain point [of technological advancement] you can send but if it's over a certain point you can't send it."

The Canadian chapter of Army SOS, an international effort to help Ukraine, lacks charitable status. Even so, Mr. Hareychuk said he's been surprised by the generosity.

Story continues below advertisement

"Our biggest donor was $10,000," he said.

The organization purchased a surveillance drone for Ukraine but it was eventually shot down by Russian-backed rebels.

Mr. Hareychuk said he was so emotionally invested in that drone shipment "I almost cried" when he was informed of its demise.

Recent donations to Army SOS have funded sterile orthopedic drills for use in military hospitals.

The OSCE's Mr. Bociurkiw said the human cost of the Ukraine war is rising.

So many people in eastern Ukraine have been forced to flee their homes because of the fighting that Ukraine now ranks among the top 10 countries when it comes to numbers of displaced people.

Story continues below advertisement

"Right now we're on the cusp of a worsening humanitarian situation," he said.

Russia's ambassador to Canada is calling on Stephen Harper to press Ukraine to hold direct talks with the rebels in eastern Ukraine. Alexander Darchiev told Global TV's West Block program that it's time for Kiev to undertake deep constitutional reform that gives regions more autonomy and makes Russian one of the country's international languages.

Mr. Harper met with Ukrainian president Petro Poroshenko and Prime Minister Arseniy Yatsenyuk Saturday to demonstrate solidarity with Ukraine. He's so far resisted Kiev's request for defensive weapons to beat back the pro-Moscow separatists.

He announced a $5-million project Saturday that will deploy up to 10 Canadian police officers across Ukraine to help reform the country's security sector. Canada is partnering with the United States and the Ukrainian government to build a new civilian patrol police force.

The objective of the project is to help change the way police interact with the public and the manner in which they fight crime and handle emergencies. Canada will focus on community policing, where officers are out in neighbourhoods and it will supply protective gear and uniforms.