Mozambican opposition leader Venâncio Mondlane called for fresh protests against the results of last month’s election and encouraged supporters to target trade routes with neighbouring South African and Zimbabwe.

The fiery former lawmaker, who rejects the outcome of the October 9 ballot as fraudulent, urged truck drivers plying the routes to the Beira port in the center of the country and Maputo port in the south to blockade them for three days, starting Wednesday.

The call ratchets up risks to the southeast African nation’s economy, which is already straining under weeks of turmoil since the vote.

If successful, it could clog a key ferrochrome export route for South Africa — the world’s biggest producer of the stainless-steel ingredient. Beira is an important port for landlocked Zimbabwe and is also used by copper mines in Zambia and the Democratic Republic of Congo.

“We will paralyse all activities,” Mondlane said in a live stream late Monday. “We will ask all truck drivers to take time off during these three days.”

His previous call for protests last week led to the temporary closure of Mozambique’s main land border with South Africa, one of the region’s busiest crossings.

The demonstrations have also interrupted commercial activity in Maputo, the capital, and raised concerns about further delays to a $20-billion natural gas export project led by TotalEnergies SE.

Dozens of people have died since the demonstrations began, according to the Centre for Democracy and Human Rights, after police used teargas and live ammunition to disperse protesters.

The government has deployed the army to the streets of Maputo and the border crossing with South Africa at Ressano Garcia, where rioters last week torched buildings and vehicles.

Mondlane also called for demonstrations in each of Mozambique’s provincial capitals. He said supporters shouldn’t force anyone to protest, and he’s repeatedly urged peace.

Mozambique’s ruling-party candidate Daniel Chapo was declared the winner of the presidential elections with nearly 71% of the vote, while Mondlane came second with 20%.

Local and international observers have raised concerns over a raft of irregularities, including signs of ballot box stuffing and altering the tallies.

The party backing Mondlane challenged the outcome with the Constitutional Council, which is yet to proclaim the final results. In the 2019 general elections, it took until December 23 to do so.