George Galloway's party unseats Labour council leader, but campaign is tinged by complaints of violence and harassment

Stones were thrown, the police were called and tempers reached boiling point – but George Galloway's electoral winning streak continued in Bradford when five rookies from his Respect party won seats on the city council, including one snatched from its Labour leader.

Ian Greenwood, who has run the council since 2010 and has been a Bradford councillor for 17 years, lost his £50,000-a-year job.

After three recounts, he was defeated by 17 votes by Alyas Karmani, a youth worker and onetime head of race relations for the Welsh assembly.

At a dawn afterparty which saw a specially written tune called the Bradford Spring Rap being blasted from a car stereo in the city's streets, Galloway said Karmani had "taken the head off the rotten fish that is the Bradford city council". Karmani described Respect as "the naughty children" of Bradford – "and with parents like that, what do you bloody expect?"

In a bruising campaign which resulted in police complaints of violence and harassment, Respect won three other seats from Labour and another from the Conservatives. The resurgent party contested 12 out of the 30 wards up for grabs in the Yorkshire city, hoping to capitalise on Galloway's victory in the Bradford West byelection in March.

But Respect failed to convince Bradfordians to vote yes in the referendum on whether the city should elect a mayor. Galloway had made clear he wanted to see a Respect-endorsed candidate running Bradford's city hall – himself, if no better contender could be found. Yet on a 35% turnout, 55.1% voted to stick with the current system.

It was not the most dignified campaign on any front. By the time polls closed on Thursday night, police were investigating two incidents of alleged violence and harassment involving Respect, Labour and the Liberal Democrats.

The Lib Dem MP for Bradford East, David Ward, has made a formal complaint to police after allegedly being "harassed and intimidated" by Respect campaigners. Jeanette Sunderland, the leader of Bradford Lib Dems, has also given a statement to police claiming to have been assaulted by Respect supporters while out canvassing on Wednesday night.

Sunderland said: "It's the sort of behaviour we fought against from the British National party. We got rid of them and we'll get rid of these thugs too."

A spokesman for Respect denied the allegations and said the party would be making its own police complaint.

"Jeanette Sunderland assaulted our guy, not the other way around. We have three videos of the incident which we are happy to share with police to prove it," said Ron McKay, adding: "This is a complete waste of police time. It's absolutely typical Lib Dem practice in byelections, totally unscrupulous. We will have to join the queue to waste police time."

Meanwhile, one Respect campaigner – Farrukh Haroon, the brother of the Respect leader Salma Yaqoob – called police after being allegedly attacked by Labour supporters on Thursday.

Haroon, 36, says he was outside the Iqra school polling station in the Manningham area of the city when his car was surrounded by Labour campaigners who yanked off his wing mirror and pulled the keys from the ignition, breaking them into three pieces.

At the election count, Ward said the behaviour of Respect was an "enormous step back for community cohesion in Bradford". He accused campaigners of following him in a car when he was out on the stump, calling out "David Ward is a liar" through a megaphone.

On Thursday night, a video was posted on Facebook, taken from the open top deck of the Respect battle bus, which showed party campaigners decrying their Labour counterparts as "criminals who have murdered a million Iraqis".

But Respect's Tazeem Sawaiz, a 44-year-old youth worker who came third to the Lib Dems and Labour in the Bolton and Undercliffe ward, claimed stones had been thrown at her while she was campaigning on the open-top bus.

Karmani, who runs a national youth project and made a documentary for Channel 4 about sexual violence among Pakistani Muslims in Britain, said Respect had a hard fight ahead. "The battle has begun now," he told supporters. "They are going to be gunning for us. Every mistake we make, the way we represent ourselves."

Referring to Galloway's claim to have "smashed" clan politics in Bradford – the so-called Biraderi system, which encouraged ethnic bloc voting – Karmani said the party had a duty to unite and not divide. "It's so important for us to make our family as open and inclusive and welcoming as possible. People are looking to us as role models," he said.

Before Thursday's election, Bradford council was run by a minority Labour-led administration. Three votes short of a majority, Labour required help from the trio of Greens on the council to pass key motions.

Despite making a few gains from the Conservatives and the Liberal Democrats, Labour was denied an overall majority when Greenwood lost Little Horton to Respect. Labour now holds 45 seats — exactly half of the 90 in the whole administration. With three Greens still in office, it is they who will have the balance of power, rather than Respect.