From Washington, this is VOA news. I'm Steve Miller reporting.

British police say they are dealing with an incident at London Bridge.

Witnesses say a van hit several pedestrians.

The bridge and nearby underground station are currently closed.

The situation is still developing and visit voanews.com for updates to this story.

U.S. President Donald Trump said he represented "the citizens of Pittsburgh, not Paris" when he announced that the United States would withdraw from the Paris accord.

Pittsburgh Mayor Bill Peduto said he was "personally offended" by Trump's remarks as he looked towards the future.

"Pittsburgh is really the model city in this country of showing how innovation and change, through sustainability, can help to bring back an economy. So my message is to make sure that the rest of this country and the rest the world understands we are not this backwater little town that is suffering and needs to look at our past for our future."

Peduto responded to Trump's statement with an executive order recommitting the city's government to its goals of cutting energy use by half and sourcing its energy from renewable sources by 2030.

A growing list of mayors, governors and businesses are pledging to step up their actions so the United States will meet the commitments agreed to in Paris during the 2015 accord.

However, experts say it is unclear whether they can actually fill the gap left by the Trump administration.

At least four Afghans were killed when protesters demanding better security clashed with riot police in Kabul on Friday.

More than a thousand demonstrators gathered Friday near the site of a blast and marched towards the presidential palace, demanding the resignation of the Afghan government.

Riot police used [cannons and] water-cannons and tear gas to push the protesters back.

This is VOA.

Speaking at the annual Shangri-La annual security forum in Singapore Saturday, U.S. Secretary of Defense James Mattis applauded China's efforts to work with the international community on North Korea. However, when it came to the South China Sea, he called China's ongoing militarization of man-made islands and its disregard for international order unacceptable.

"Artificial island construction and indisputable militarization of facilities on features in international waters undermine regional stability. The scope and effect of China's construction activities in the South China Sea differ from those of other countries in several key ways. This includes the nature of its militarization, China's disregard for international law, its contempt for other nations' interests, and its efforts to dismiss non-adversarial resolution of issues."

His tough remarks dispelled speculation by some that the administration was keeping quiet about the South China Sea in exchange for China's cooperation in dealing with Pyongyang. Mattis said the interests of the United States allies would not be used as bargaining chips.

Citizens of the African nation of Lesotho are voting in national elections Saturday. More from VOA's Anita Powell.

The most visible figures in Lesotho's capital during this election weren't the long lines of voters who clustered together for warmth eager to be in place before polls opened. They were the squads of uniformed soldiers lurking at safe distance from many polling stations, especially in the opposition heavy capital, Maseru.

The head of the nation's electoral commission said in a tweet that he was concerned about their presence and that he had reported their presence to observers.

"We have to vote, definitely we have to vote, so that we elect someone who we think is going to make life easier for us. So we want some change."

Results are expected Monday.

Anita Powell, VOA news, Maseru, Lesotho.

A spokesman for the Syrian Kurdish militia group YPG says U.S.-backed military forces in Syria are poised to launch in an offensive to capture the Islamic State's de facto capital of Raqqa in a few days.

The spokesman confirmed Saturday remarks by American military officials who said on Thursday that the Syrian Democratic Forces have pushed to within three kilometers of Raqqa.

Speaking in Baghdad, the U.S.-led counter IS coalition spokesman, Colonel Ryan Dillon, confirmed.

In Washington, I'm Steve Miller.

That's the latest world news from VOA.