BAGHDAD – A suicide bomber struck a crowd of funeral mourners Monday north of Baghdad, taking more than 30 lives at the end of one of the deadliest months of the war so far for U.S. forces. At least 104 American troops were reported killed in April.

The rising toll among Americans pointed to a potentially deadly trend: More troops exposed to more dangers as they try to reclaim control of Baghdad under the joint security plan being implemented by U.S. and Iraqi forces.

Bombings and shootings nationwide Monday killed at least 102 people, counting the funeral attack.

After sunset, there was no let up. Thunderous explosions rocked central Baghdad – apparently from rockets fired toward the U.S.-controlled Green Zone. Warning sirens sounded in the heavily protected district, and witnesses saw smoke rising from the area. The U.S. military said it had no immediate information about damage or casualties.

The rockets appeared to come from a part of eastern Baghdad where Shiite militiamen operate. But the barrage suggested that Shiite gangs could be regrouping after falling back when the Baghdad security sweeps got under way.

Five U.S. military deaths were announced Monday. All but one occurred over the weekend in Iraq’s capital, where a nearly 11-week security crackdown has put thousands of additional American soldiers on the streets – making them targets for both Shiite and Sunni extremists.

In a statement, the U.S. command said three American soldiers and an Iraqi interpreter were killed by a roadside bomb Sunday in eastern Baghdad. Another U.S. soldier was killed Saturday by small arms fire in the same area, the statement said.

A Marine died in combat Sunday in Anbar province, a Sunni insurgent stronghold west of the capital, the military said.

The 104 deaths among American service members in Iraq in April were eight fewer than December’s toll of 112, and the sixth-highest figure for a single month since the war started in March 2003.

Last week, the top U.S. commander in Iraq, Gen. David Petraeus, warned in Washington that “there is the very real possibility” of intense combat in the coming months and “therefore, there could be more casualties.”

President Bush has committed some 30,000 extra American troops to the security operation in Baghdad, but he is facing legislation by the Democratic-led Congress calling for U.S. troops to begin withdrawing from Iraq by Oct. 1. Bush has promised to veto the measure.

While American casualties are rising, U.S. officials say the Baghdad crackdown has reduced civilian deaths in the capital since the security operation was launched Feb. 14.

But figures compiled by The Associated Press from police reports show a rise in civilian casualties outside the capital, where extremists took refuge to avoid the Baghdad operation.

Police said 32 people were killed and 63 wounded when the suicide bomber struck the Shiite funeral in Khalis, about 50 miles north of Baghdad. The bomber walked into a tent filled with mourners and detonated a belt of explosives hidden beneath his clothes, police said.

Attacks on funeral gatherings are not uncommon. Suicide attacks are the hallmark of Sunni religious extremists, notably al-Qaida in Iraq.

Elsewhere, a tanker truck exploded near a restaurant just west of Ramadi, the capital of Anbar province, killing four people and wounding six, police said.

At least 66 other people were killed or found dead nationwide Monday, police reported. They included 27 bullet-riddled bodies found in Baghdad, apparent victims of sectarian death squads.