PORTLAND — Passers-by Monday on Middle Street looked toward the ground, where a handful of protesters lay motionless, covered in sheets that looked bloodied. They covered their faces with placards that bore the names of Yemeni wedding party members who were killed by a U.S. drone strike in December.

One protester held aloft a model drone, symbolizing what members of Code Pink, the group that organized the demonstration, say is the constant threat of bombing that civilians in the Middle East face every day. Another activist used her mobile phone to play the buzzing sound of drones flying overhead.

After the bit of street theater ended, Mark Roman, a protester from Solon, said that as he lay there, he felt “tremendously sad, and also pretty angry.

“I’m thinking about these people celebrating a wedding, and my government is killing them,” he said.

The group of eight Code Pink protesters gathered outside Republican U.S. Sen. Susan Collins’ Portland office to urge Collins to support an amendment to the Intelligence Authorization Act that would require the Central Intelligence Agency to disclose the number of civilian deaths attributable to drone strikes.

At a meeting of the Senate Intelligence Committee in November, Collins voted against the amendment, which was proposed by Sen. Dianne Feinstein, D-Calif. The measure ultimately passed 8-7 along party lines. However, Collins joined two other Republicans in supporting the final spending bill.

In a memo circulated to Intelligence Committee members, President Barack Obama’s Department of Defense opposed the Feinstein amendment, saying a public account of all drone strikes would lead to the release of sensitive information that could “help the enemy analyze our operations and potentially gain an advantage to thwart future counterterrorism efforts.”

Despite Collins’ vote in favor of the full bill, Maine’s Code Pink contingent said they wanted the senator to change her position on civilian drone death disclosure. They argued Monday that her voice as a moderate member of the GOP would embolden other Republicans to support disclosure.

Alice Savage, a schoolteacher and Code Pink’s coordinator in Maine, joined two other activists in delivering a petition with more than 300 signatures to Collins’ office. An intern said he would pass the stack of papers on to the senator.

“I fully expected him to refuse the petition, but I’m glad he took it,” said Savage, who is also Roman’s wife. “This is how democracy should work.”

The CIA keeps a record of the civilians it believes have been killed by drones, but that information is kept secret. However, civilian casualties have been reported by journalists and locals in Pakistan, Yemen and Somalia.

Kevin Kelley, a spokesman for Collins, said in a written statement Monday that the senator’s “concern about the president’s largely unfettered authority to issue drone strikes” caused her to join an effort to compel Obama to release legal justifications for the use of unmanned aircraft.

In February, Collins also questioned CIA Director John Brennan during his nomination hearing about whether blowback from the use of drone strikes undermined U.S. national security interests.