Former guerrilla commander Salvador Sanchez Ceren was sworn in Sunday as president of El Salvador with the pressing tasks of dealing with violent gangs, a struggling economy and endemic poverty.

Sanchez Ceren, 69, promised to govern "with honesty, austerity, efficiency and transparency."

Afghanistan said on Sunday it was pulling out of security talks in Islamabad in anger at cross-border attacks blamed on the Pakistan army, which it said were designed to disrupt the second round of its presidential election.

In a meeting chaired by President Hamid Karzai, the National Security Council "condemned" increasing numbers of "rocket attacks (by the) Pakistani military against the country," a statement from the presidential palace said.

Turkish police on Sunday fired tear gas and water cannon at hundreds of protesters in Ankara a day after violent clashes on the one-year anniversary of the country's largest anti-government demonstrations in decades.

Police stepped in to disperse around 500 people from Ankara's downtown Kizilay Square who wanted to stage a demonstration at the site where a 26-year-old protester was shot and killed by police the same day last year, an Agence France Presse photographer said.

The Organization for Security and Cooperation in Europe said on Sunday it still had no news from two teams detained in eastern Ukraine by separatist gunmen despite reports of their release.

The Vienna-based security body said both a four-member international team nabbed in the Donetsk region on Monday and another four European monitors and their local translator abducted in neighboring Lugansk on Thursday remained out of contact.

U.S. Defense Secretary Chuck Hagel expressed hope Sunday the release of U.S. Army Sergeant Bowe Bergdahl would lead to direct U.S. talks with the Taliban, as the extremist movement's leader hailed the prisoner swap as a “big victory.”

"It could, it might and we hope it will present an opening," Hagel said in an interview from Bagram Air Base in Afghanistan with NBC's "Meet the Press."

Qatar on Sunday said it has mediated the swap of a captured U.S. soldier for five Taliban members out of “humanitarian” concern.

"When it comes to humanitarian matters, the Emir does not hesitate," Qatari Foreign Minister Khaled al-Attiyah said.

Popular video-sharing site YouTube remained blocked in Turkey on Sunday despite the country's top court ruling that the blanket ban contravened the right to free speech. 

Turkey's constitutional court ruled Thursday that the ban on YouTube violated individual rights and freedoms, clearing the way for access to the service to be revived following a two-month ban.

A co-owner of The Philadelphia Inquirer and six other people were killed when a private business jet crashed during takeoff from an airfield outside Boston.

The Gulfstream IV jet burst into a fireball upon crashing late Saturday at LG Hanscom Field, located just northwest of Boston, killing all aboard.

Sri Lanka's navy said Sunday it had seized 29 Indian fishermen, the  first arrests since President Mahinda Rajapakse and India's new premier held talks on resolving the thorny issue of poaching.

The navy arrested the Indians along with six trawlers off the island's northwest coast on Sunday, a navy statement said.

Pro-democracy protesters marched in Hong Kong on Sunday to call for greater political freedoms in China and an end to one-party rule, ahead of the 25th anniversary of the Tiananmen Square crackdown.

Organizers said 3,000 people took to the streets in sweltering heat for the annual protest, calling on Beijing to release imprisoned political dissidents and formally acknowledge the bloody crackdown of 1989.