Police fired teargas at opposition supporters who rallied in Kenya’s capital Nairobi on Monday calling for the sacking of election board officials they blame for August’s botched presidential vote.

Officers also clashed with crowds and fired teargas in the western opposition stronghold of Kisumu, forcing businesses to close, a Reuters witness said. Local media reported scattered protests in other western towns and the port city of Mombasa.

Kenya’s Supreme Court voided the Aug. 8 election citing irregularities, without finding any individual at the election board responsible.

President Uhuru Kenyatta, who won the August vote only to have his victory annulled, has accused the Supreme Court of bringing the country close to “judicial chaos”. Opposition leader Raila Odinga and his supporters have turned their ire on the election board, accusing it of wrongly handing the August vote to Kenyatta.

Supporters from both sides have traded insults and accusations, raising fears tensions could boil over into ethnic violence, as in 2007 when 1,200 people were killed after a disputed election.

In the capital of the East African economic powerhouse, police fired rounds of teargas at small groups over several hours in at least three locations in the downtown business district, a Reuters witness said.

After a meeting with the election board, British and U.S. diplomats condemned “inflammatory rhetoric” by politicians and said it undermined the voting authorities’ preparations for the new election.

In the first signal that Western governments might take concrete action against hate speech, a British diplomat told reporters: “Anyone who is found to be inciting or engaging in violence must be held accountable … the UK reserves right to take appropriate action which may include refusing or revoking visas.”

Kenyatta and Odinga have been sparring over proposed changes to the election system to prevent the Supreme Court from annulling the results again, raising doubts about the date of the re-run, currently scheduled for Oct. 26.

Kenyatta said on Monday opposition supporters should accept the Supreme Court’s timeline for the new poll.

“You can’t have your cake and eat it,” he said at an event in Nairobi. “If you celebrated the court’s decision to repeat the election you must also respect the court’s decision to have (the election board) preside over the repeat election within 60 days.”