Image copyright AP Image caption Part of the increase is attributable to Egypt's use of death sentences against Islamists

Human rights group Amnesty International has said there was an "alarming" increase in death sentences around the world in 2014.

In its annual review of death penalty use across the planet, it said some countries were using it in response to "real or perceived" security threats.

More than 500 more death sentences were issued than in 2014, mainly because of sharp rises in China and Nigeria.

However, excluding China, the number of actual executions reportedly dropped.

Amnesty recorded 607 executions in 2014, down almost 22% on 2013. However, this figure does not include China, which executes more people than the rest of the world put together but keeps the exact numbers a state secret.

Executions were recorded in 22 countries in 2014, the same number as in the previous year.

Apart from China, Amnesty said the world's top executioners in 2014 were:

Iran - 289 executions announced officially, and at least 454 not acknowledged by the authorities

Saudi Arabia - at least 90

Iraq - at least 61

the US - 35

In Egypt, hundreds of people have been sentenced to death in mass trials over the past two years in a crackdown on Islamists. The trials have drawn widespread international criticism, with the UN describing them as "unprecedented".

In Nigeria, 659 death sentences were recorded in 2014, Amnesty said, a jump of more than 500 compared with the previous year.

Military courts handed down death sentences against dozens of soldiers during the year in separate trials. They were convicted of mutiny in the context of the armed conflict with Islamist militants Boko Haram.

Earlier this month Pakistan lifted a seven-year moratorium on executions in the wake of a Taliban massacre at a school in the city of Peshawar in December.