HARARE, Zimbabwe (AP) -- Britain has sent a formal diplomatic complaint to Zimbabwean authorities protesting harassment of a diplomat and attempts by ruling party supporters to disrupt the handover of a British aid project, officials said Friday.

In a statement, the British embassy said Mugabe's party bussed protesters to a mission hospital in eastern Zimbabwe where the diplomat, second secretary Sarah Bennett, handed over British-funded hospital equipment.

Demonstrators mobbed local officials and visiting dignitaries, demanding the lifting of Western economic sanctions targeted at Mugabe and his ruling elite. It was "deeply depressing" the project was subjected to party propaganda, the statement said.

No violence was reported, but the incident came amid rising political tensions and a new upsurge in political violence across Zimbabwe ahead of elections proposed later this year.

Bennett was in the remote Mutasa rural district Wednesday to donate mortuary equipment the area had long lacked.

Rowdy demonstrators carried placards describing Prime Minister Morgan Tsvangirai, the former opposition leader in a fragile two-year power sharing coalition with Mugabe, as a "puppet" of the West.

British Ambassador Mark Canning said in Friday's statement that Britain spent more than $100 million in aid for local communities last year.

He dismissed claims that visa, business and banking sanctions on Mugabe and his ZANU-PF party by Britain and European Union hurt Zimbabweans as a whole.

"Only 1 in 70,000 Zimbabweans are affected by the EU's restrictive measures - because they are targeted at those responsible for human rights abuses and behavior which undermines democracy and good governance," he said.

On Sunday, human rights activists reported that political tensions and violence rose markedly in January ahead of proposed elections this year even though a date for the vote has not been scheduled yet.

Mob attacks, threats, assaults, questionable arrests by police and at least one shooting were reported in clashes between rival party supporters in Harare and its suburbs.

Zimbabwe's state-run radio has accused the prime minister of trying to spark anti-government uprisings similar to those seen in Tunisia and Egypt.

An independent doctors' group said Thursday it had evidence from witness accounts that at least 70 Mugabe militants were brought by truck to the western Mbare township, the center of new clashes this week that left nine people injured, three of them hospitalized.

Calm returned to downtown Harare after mobs chanting slogans of Mugabe's party besieged downtown offices of the Tsvangirai-led City Council on Wednesday.

Tsvangirai entered a coalition with Mugabe after violence-plagued elections in 2008. Mugabe has called for national elections later in 2011 to bring an end to bitter disputes over power sharing in the coalition.