Dzhokhar Tsarnaev, one of the suspects of the Boston Marathon bombings, remained in serious condition in a Boston hospital on Sunday unable to answer questions on the devastating attack.

Media reports said Dzhokhar Tsarnaev had suffered a throat wound during his cavalcade which ended late Friday after a massive manhunt in which his accomplice brother, 26-year-old Tamerlan Tsarnaev, was killed.

The Tsarnaev brothers are the main suspects in the twin bomb attack on the Boston marathon which killed three people and wounded about 180. A policeman was killed and another was left fighting for his life after gunbattles during the hunt.

Massachusetts governor Deval Patrick said he hopes the teenager survives. "We have a million questions and those questions need to be answered," he said.

Media reports say authorities did not read Tsarnaev his Miranda rights, invoking a special exception for security reasons.

This has left US authorities facing tough decisions over how to handle the investigation and any trial.

The Tsarnaev family are reportedly ethnic Chechens who moved to the US from the former Soviet state of Kyrgyzstan around 2002.

Tamerlan Tsarnaev reportedly became a fervent Muslim in recent years. Much focus is now being put on his six-month trip to the Russian region of Dagestan last year.

US President Barack Obama and Russian President Vladimir Putin agreed during a telephone conversation Saturday to increase cooperation against international terrorism.

The FBI acknowledged Friday that an unnamed foreign government, reportedly Russia, asked for information about Tamerlan Tsarnaev in 2011. The FBI interviewed the man but said it had found no "derogatory" information.

"I personally believe that this man received training when he was over there and he radicalized from 2010 to the present," Representative Michael McCaul, chairman of the House Homeland Security committee, told CNN.

Dzhokhar Tsarnaev, who became a US citizen last year, was caught after a man named Dave Henneberry saw blood on a boat he kept in his backyard in Watertown, in the Boston suburbs. When Henneberry lifted the tarp he saw the wounded teenager curled up inside, police said.

The University of Massachusetts student was surrounded for a showdown that included a final gunbattle before Tsarnaev surrendered.

Police say the brothers killed one officer and wounded another as they fled, hurling home-made bombs at their hunters.

Watertown police chief Edward Deveau said the pair had at least six bombs with them when being chased and that Dzhokhar had driven over his brother as he escaped.

Fifty-eight of the victims from the bomb attack are still in Boston hospitals, with three in critical condition.

A memorial service for Lü Lingzi, a victim of the bombings from China's Liaoning Province, will be held Monday at Boston University (BU).

The service is scheduled to start at 7 pm and will be open to the public, according to the university's news website BU Today.

Lü's family arrived in Boston on Friday night and were received by Chinese ambassador to the US Cui Tiankai, according to the Xinhua News Agency.

Boston University has set up a scholarship in the name of Lü and has already received contributions totaling $560,000, according to BU Today.

Kenneth Feld, a BU trustee who proposed the memorial scholarship Wednesday, said by honoring Lü, the scholarship recognizes BU's profound connection to China, which is sending a growing number of students to the university.

"BU has another strong connection - among many other ties, the US ambassador to China, Gary F. Locke, is an alumnus," said Feld.

In a letter sent to BU, Lü's parents said: "We hope that everyone who knew Lingzi, and experienced the positive spirit and joy she had, will help carry on her spirit."

AFP - Global Times