A woman and four children escaped injury when a bomb was thrown through the living room window of their home in North Belfast.
The Catholic woman and her children were upstairs in their Manor Street home when a white car pulled up and, according to local people, a man got out and threw the bomb.
Police said the bomb had been a "substantial device" that had contained shrapnel and caused extensive damage to the room. They are treating the attack as sectarian.
Sinn Féin claimed the attackers shouted: "Up the UDA" and yelled sectarian abuse at the house as their car sped away.
In a separate incident, a pipe-bomb was defused outside a policeman's home in Annalong on the Co Down coast. It was made safe after army bomb experts carried out two controlled explosions.
It was the second time the officer had been targeted in the house. On April 27th last year another pipe bomb was defused at the house.
Elsewhere, a man (39) was shot in the leg in a paramilitary style attack in Newtownards, Co Down. He was found lying in a laneway in the Scrabo estate in the town, police said.