Blantyre (Malawi): Malawi's President threatened opposition leaders on Friday, accusing them of treason and blaming them for the deaths of at least 18 people this week during anti-government demonstrations.

The violent response from President Bingu wa Mutharika's security forces prompted international condemnation from the United States, European Union and former ruler Britain.

In a fiery speech on Friday, Mutharika accused his estranged deputy Joyce Banda, opposition leader John Tembo and two civil society leaders of being behind the demonstrations. "The blood of these people who have died is on you," he said, "Let their spirits haunt you at night."

Mutharika said his patience was worn out: "This time I'll go after you! Even if you hide in holes I'll smoke you out!" he warned. The comments came a day after he said protesters were "being led by Satan."

Mutharika first came to power in a 2004 election, and was easily re-elected in May 2009. But tensions have been growing this year over worsening shortages of fuel and foreign currency. High unemployment alongside a deteriorating economic situation also threatened to reverse development gains made in the early years of his presidency.

This week, protesters attacked businesses belonging to the President's political allies. Looters in the capital of Lilongwe targeted shops belonging to ruling party officials, witnesses said.