Police on Monday fired teargas at opposition supporters in the Kenyan capital Nairobi who were calling for the sacking of officials they blame for last month’s botched presidential election, Reuters witnesses said.

A re-run is due to be held Oct. 26 after the Supreme Court voided the Aug. 8 vote due to irregularities. The court criticized election the board on procedural grounds but did not find any individual at the board responsible. [L5N1M119T]

In the capital, police fired rounds of teargas over the course of several hours at small groups of protesters in at least three locations in the business district downtown.

Police also fired teargas to disperse protesters in the western city of Kisumu, according to another Reuters witness. At least 28 people were killed in unrest following last month’s vote.

Businesses were paralyzed in Kisumu, an opposition stronghold, on Monday after police and demonstrators clashed.

Kenya is a key Western ally in a region often roiled by violence. It is also the richest country per capita in East Africa and a regional gateway for trade and transport.

Whether the re-run will go ahead as planned looks increasingly uncertain as the parties of the two candidates, Kenyatta and opposition leader Raila Odinga spar over proposed changes to the election system to prevent the Supreme Court from annulling the results again.

Kenyatta’s ruling Jubilee Party presented parliament with proposed changes last week but Odinga’s coalition has said it will not take part unless these are dropped.

After a meeting with the election board, British and U.S. diplomats condemned “inflammatory rhetoric” by politicians and said it undermined the election board’s ability to carry out its job of holding the new election.

In the first signal that Western governments might take concrete action against Kenyan politicians engaging in 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.”

Since the Supreme Court voided last month’s presidential results, politicians from the ruling party and the opposition have made fiery, at times crude, speeches - stoking fears that violence could take on an ethnic dimension, as in 2007, when 1,200 people were killed after a disputed election.

Also on Monday, Kenyatta said opposition supporters should accept the Supreme Court’s timeline for when the new poll must be held.

“You can’t have your cake and eat it,” he said. “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,” the president said at an event in Nairobi.