BOSTON, Massachusetts (AFP) - Boston bombing suspect Dzhokhar Tsarnaev was in serious condition in hospital and was "unable to communicate," Massachusetts Governor Deval Patrick said Sunday.

The 19-year-old is "serious but stable. I think not able to communicate yet," the governor told reporters outside the Boston Red Sox baseball ground where he attended a tribute to the city after Monday's bomb attacks that left three dead and about 180 injured.

Dzhokhar Tsarnaev was detained on Friday but had been badly wounded. His elder brother Tamerlan was killed in a shootout with police earlier in the day during a massive manhunt.

Patrick said he hopes the teenaged suspect survives. "We have a million questions and those questions need to be answered," he added.