Explosions heard in Kabul following John Kerry's visit

Several explosions were heard in the diplomatic area of central Kabul on Saturday night, shortly after the US Secretary of State John Kerry left the capital after official meetings with Afghan officials including President Ashraf Ghani.

Gunshots were also heard, but authorities could not confirm immediately the nature of the blasts.

"We heard several explosions, but we don't know what caused them," a police official told AFP on condition of anonymity.

The explosions followed a relatively calm period for the city. It's known that the Taliban frequently attacks government and military installations in Kabul.

Kerry's visit came as Afghanistan tries to bring the Taliban back to the negotiating table, which is stronger it has been since the time they were toppled from power in late 2001, as a US-led coalition occupied the country and helped form a new government, following the September 11 attacks.

The militant group has so far refused to talk until their conditions are met, including the departure of 13,000 foreign soldiers - some 9,800 of whom American - from Afghanistan.

Kerry repeated in his visit an offer of peace talks with the Taliban.

"We call on the Taliban to enter into a peace process, a legitimate process that brings an end to violence," he said in a joint conference with Ghani. "Of course there is hope for peace."

The Afghan government, after being elected in 2014, was on a peace process with Taliban. The two sides met in last July in Islamabad, but efforts for peace talks, including the US, China and Pakistan, stopped after it emerged later that month that the Taliban's founder Mullah Omar was dead.

Besides Taliban getting stronger, Afghanistan also deals with fractious politics. Kerry also called on Afghan politicians to come together.

"Democracy requires... a willingness of people from different political and ethnic and geographic factions to be able to come together and work for a common good," he said.