Demonstrators in Ecuador clash with riot police during a protest over a fuel price hike ordered by the government to secure an IMF loan

Riot police clashed with indigenous demonstrators in Ecuador's capital on Friday as deadly protests against fuel price hikes stretched into a 10th day.

Protesters responded to volleys of tear gas with homemade mortars and fireworks launched through tubes, turning the area around the Congress building in Quito into a battleground.

Indigenous groups have spearheaded demands that President Lenin Moreno reinstate fuel subsidies that were cut last week, part of a deal his government struck to obtain a $4.2 billion loan from the IMF.

On Thursday, indigenous leaders called for a "radicalization" of the protests that have brought much of the capital to a standstill and forced Moreno to relocate his government to Ecuador's second city, Guayaquil.

The crisis has seen more than 550 people wounded and about a thousand detained, according to the ombudsman's office.

The United States expressed its support for Moreno's government Friday.

"We recognize the difficult decisions that the Government of Ecuador has taken to advance good governance and promote sustainable economic growth," Secretary of State Mike Pompeo said in a statement.

"We are aware and monitoring claims of external actor involvement in these demonstrations," Pompeo said.

Struggling to deal with an economic crisis, Moreno has accused his predecessor and ex-ally Rafael Correa along with Venezuelan President Nicolas Maduro of an "attempted coup d'etat" using indigenous groups.

Maduro, a leftist firebrand whom Washington is seeking to oust, has denounced allegations of involvement as absurd, but praised the "popular insurrection" against the IMF.

Apawki Ctro, spokesman for indigenous umbrella group CONAIE, said around 1,000 more indigenous people arrived in the city on Friday and another group is arriving to bolster the demonstrators.

CONAIE claimed around 20,000 indigenous people arrived in the capital last weekend from disadvantaged outlying communities in the Amazon and the Andes.

They joined trade union workers and students in a major protest against the subsidy cuts on Wednesday. It ended violently, leaving four protesters dead, including an indigenous leader.

The deaths announced on Thursday brought the overall toll in the protests to five. The first victim was hit by a vehicle on Sunday in the southern province of Azuay.

Demonstrators in Ecuador clash with riot police during a protest over a fuel price hike ordered by the government to secure an IMF loan