Pensioners hit with pepper spray in Caracas

Venezuelan police on Friday blocked a march by some 2,000 elderly protesters, some of them in wheelchairs, who were demonstrating in Caracas against President Nicolas Maduro's socialist government and demanding subsidies for food and medicines.

Riot police with helmets and shields used pepper spray several times in a bid to control the crowd, according to opposition politicians. The protesters had intended to march to the office of the country's human rights ombudsman.

Opposition leader Henrique Capriles criticized the use of force against elderly people.

"No one has the right to attack a grandpa. they are the moral reserve of the country," he said.

Since launching protests against Maduro in early April, the opposition has been employing a number of tactics, staging rallies for women, musicians and medics. It is planning a "march of mothers" for Sunday.

The ruling socialist government has tried to respond in kind each time. On Friday, it held its own rival old people's rally in front of the Miraflores presidential palace, where protesters called out slogans in support of Maduro and his late predecessor Hugo Chavez.

Collapse in oil revenue

At least 39 people have died and 800 been injured in the protests, which highlight the suffering of Venezuelans amid an economic crisis that has led to drastic shortages of food and medicine in the oil-rich country. The Health Ministry on Wednesday issued data showing an increase of 30 percent in the deaths of babies aged less than one in 2016, while 65 percent more women died of causes linked to childbirth.

Read: Venezuela sees a sharp rise in child mortalities

The health minister, Antonieta Caporale, was dismissed the day after the 2016 figures were released, although she took over the post only in January of this year.

The shortage of medicines and other essential supplies has been caused by a collapse in prices for Venezuela's oil exports. Maduro, who is resisting opposition pressure to call early elections, has called the crisis a US-backed conspiracy.